<?xml version="1.0" encoding="utf-8"?>
<!--XBRL document created with Toppan Merrill Bridge  10.9.0.3 -->
<!--Based on XBRL 2.1-->
<!--Created on: 3/31/2025 12:14:52 PM-->
<!--Modified on: 3/31/2025 12:14:52 PM-->
<link:linkbase xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xlink="http://www.w3.org/1999/xlink">
  <roleRef xlink:type="simple" xlink:href="mrkr-20241231.xsd#StatementConsolidatedBalanceSheets" roleURI="http://www.tapimmune.com/role/StatementConsolidatedBalanceSheets" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="mrkr-20241231.xsd#StatementConsolidatedStatementsOfOperations" roleURI="http://www.tapimmune.com/role/StatementConsolidatedStatementsOfOperations" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="mrkr-20241231.xsd#DisclosureConsolidatedStatementsOfCashFlowsCalc2" roleURI="http://www.tapimmune.com/role/DisclosureConsolidatedStatementsOfCashFlowsCalc2" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="mrkr-20241231.xsd#StatementConsolidatedStatementsOfCashFlows" roleURI="http://www.tapimmune.com/role/StatementConsolidatedStatementsOfCashFlows" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="mrkr-20241231.xsd#DisclosureDiscontinuedOperationsOperationsDetails" roleURI="http://www.tapimmune.com/role/DisclosureDiscontinuedOperationsOperationsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="mrkr-20241231.xsd#DisclosureDiscontinuedOperationsCashFlowsDetails" roleURI="http://www.tapimmune.com/role/DisclosureDiscontinuedOperationsCashFlowsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="mrkr-20241231.xsd#DisclosureAccountsPayableAccruedLiabilitiesAndRelatedPartyPayableDetails" roleURI="http://www.tapimmune.com/role/DisclosureAccountsPayableAccruedLiabilitiesAndRelatedPartyPayableDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="mrkr-20241231.xsd#DisclosureIncomeTaxesSummaryOfEffectsOfTemporaryDifferencesThatGiveRiseToSignificantPortionsOfDeferredTaxAssetsDetails" roleURI="http://www.tapimmune.com/role/DisclosureIncomeTaxesSummaryOfEffectsOfTemporaryDifferencesThatGiveRiseToSignificantPortionsOfDeferredTaxAssetsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="mrkr-20241231.xsd#DisclosureIncomeTaxesScheduleOfExpectedTaxExpenseBenefitFromContinuingOperationsDetails" roleURI="http://www.tapimmune.com/role/DisclosureIncomeTaxesScheduleOfExpectedTaxExpenseBenefitFromContinuingOperationsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <link:arcroleRef arcroleURI="https://xbrl.org/2023/arcrole/summation-item" xlink:type="simple" xlink:href="https://www.xbrl.org/2023/calculation-1.1.xsd#summation-item" />
  <calculationLink xlink:role="http://www.tapimmune.com/role/StatementConsolidatedBalanceSheets" xlink:type="extended" xlink:title="995200100 - Statement - CONSOLIDATED BALANCE SHEETS" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Assets" xlink:label="Assets" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent_638790200893064968" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="Assets" xlink:to="us-gaap_AssetsCurrent_638790200893064968" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_638790200893064968" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_638790200893064968" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_638790200893064968" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="us-gaap_PrepaidExpenseCurrent_638790200893064968" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_638790200893064968" xlink:to="us-gaap_PrepaidExpenseCurrent_638790200893064968" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherReceivablesNetCurrent" xlink:label="us-gaap_OtherReceivablesNetCurrent_638790200893074971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_638790200893064968" xlink:to="us-gaap_OtherReceivablesNetCurrent_638790200893074971" order="3" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="LiabilitiesAndStockholdersEquity" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities_638790200893074971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_Liabilities_638790200893074971" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent_638790200893074971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities_638790200893074971" xlink:to="us-gaap_LiabilitiesCurrent_638790200893074971" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="us-gaap_OtherLiabilitiesCurrent_638790200893074971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent_638790200893074971" xlink:to="us-gaap_OtherLiabilitiesCurrent_638790200893074971" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_638790200893074971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent_638790200893074971" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_638790200893074971" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_638790200893084971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_StockholdersEquity_638790200893084971" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue_638790200893084971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_638790200893084971" xlink:to="us-gaap_PreferredStockValue_638790200893084971" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue_638790200893084971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_638790200893084971" xlink:to="us-gaap_CommonStockValue_638790200893084971" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital_638790200893084971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_638790200893084971" xlink:to="us-gaap_AdditionalPaidInCapital_638790200893084971" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_638790200893084971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_638790200893084971" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_638790200893084971" order="4" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.tapimmune.com/role/StatementConsolidatedStatementsOfOperations" xlink:type="extended" xlink:title="995200200 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_638790200893094971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_638790200893094971" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" xlink:label="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax_638790200893094971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_638790200893094971" xlink:to="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax_638790200893094971" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax" xlink:label="us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax_638790200893094971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_638790200893094971" xlink:to="us-gaap_DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax_638790200893094971" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeLossFromContinuingOperations" xlink:label="us-gaap_IncomeLossFromContinuingOperations_638790200893094971" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_IncomeLossFromContinuingOperations_638790200893094971" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit_638790200893105030" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperations_638790200893094971" xlink:to="us-gaap_IncomeTaxExpenseBenefit_638790200893105030" order="1" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_638790200893105030" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperations_638790200893094971" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_638790200893105030" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIncomeInterest" xlink:label="us-gaap_InvestmentIncomeInterest_638790200893105030" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_638790200893105030" xlink:to="us-gaap_InvestmentIncomeInterest_638790200893105030" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss_638790200893105030" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_638790200893105030" xlink:to="us-gaap_OperatingIncomeLoss_638790200893105030" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses_638790200893105030" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss_638790200893105030" xlink:to="us-gaap_OperatingExpenses_638790200893105030" order="1" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense_638790200893114969" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_OperatingExpenses_638790200893105030" xlink:to="us-gaap_GeneralAndAdministrativeExpense_638790200893114969" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense_638790200893114969" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_OperatingExpenses_638790200893105030" xlink:to="us-gaap_ResearchAndDevelopmentExpense_638790200893114969" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_638790200893114969" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss_638790200893105030" xlink:to="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_638790200893114969" order="2" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.tapimmune.com/role/DisclosureConsolidatedStatementsOfCashFlowsCalc2" xlink:type="extended" xlink:title="00400 - Disclosure - CONSOLIDATED STATEMENTS OF CASH FLOWS (calc 2)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProfitLoss" xlink:label="us-gaap_ProfitLoss_1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_638790200893114969" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_ProfitLoss_1" xlink:to="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax_638790200893114969" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_638790200893114969" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_ProfitLoss_1" xlink:to="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_638790200893114969" order="2" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.tapimmune.com/role/StatementConsolidatedStatementsOfCashFlows" xlink:type="extended" xlink:title="995200400 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:label="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_638790200893125079" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_638790200893125079" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations_638790200893125079" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_638790200893125079" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations_638790200893125079" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_638790200893125079" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations_638790200893125079" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_638790200893125079" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInDueToRelatedPartiesCurrent" xlink:label="us-gaap_IncreaseDecreaseInDueToRelatedPartiesCurrent_638790200893125079" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations_638790200893125079" xlink:to="us-gaap_IncreaseDecreaseInDueToRelatedPartiesCurrent_638790200893125079" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet" xlink:label="us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet_638790200893134958" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations_638790200893125079" xlink:to="us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet_638790200893134958" order="3" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:label="us-gaap_IncreaseDecreaseInPrepaidExpense_638790200893134958" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations_638790200893125079" xlink:to="us-gaap_IncreaseDecreaseInPrepaidExpense_638790200893134958" order="4" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation_638790200893134958" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations_638790200893125079" xlink:to="us-gaap_ShareBasedCompensation_638790200893134958" order="5" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_638790200893134958" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations_638790200893125079" xlink:to="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_638790200893134958" order="6" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations" xlink:label="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations_638790200893134958" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_638790200893125079" xlink:to="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations_638790200893134958" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_638790200893134958" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_638790200893134958" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations" xlink:label="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_638790200893144956" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities_638790200893134958" xlink:to="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_638790200893144956" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_638790200893144956" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_638790200893144956" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="mrkr-20241231.xsd#mrkr_ProceedsFromIssuanceOfCommonStockAndWarrantsNet" xlink:label="mrkr_ProceedsFromIssuanceOfCommonStockAndWarrantsNet_638790200893144956" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_638790200893144956" xlink:to="mrkr_ProceedsFromIssuanceOfCommonStockAndWarrantsNet_638790200893144956" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_638790200893144956" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_638790200893144956" xlink:to="us-gaap_ProceedsFromStockOptionsExercised_638790200893144956" order="2" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.tapimmune.com/role/DisclosureDiscontinuedOperationsOperationsDetails" xlink:type="extended" xlink:title="99940601 - Disclosure - DISCONTINUED OPERATIONS - Operations (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" xlink:label="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense_638790200893144956" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense_638790200893144956" order="1" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_638790200893154946" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_638790200893154946" order="2" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.tapimmune.com/role/DisclosureDiscontinuedOperationsCashFlowsDetails" xlink:type="extended" xlink:title="99940602 - Disclosure - DISCONTINUED OPERATIONS - Cash Flows (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetCashProvidedByUsedInDiscontinuedOperations" xlink:label="us-gaap_NetCashProvidedByUsedInDiscontinuedOperations" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations" xlink:label="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_638790200893154946" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInDiscontinuedOperations" xlink:to="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_638790200893154946" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations" xlink:label="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations_638790200893154946" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInDiscontinuedOperations" xlink:to="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations_638790200893154946" order="2" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.tapimmune.com/role/DisclosureAccountsPayableAccruedLiabilitiesAndRelatedPartyPayableDetails" xlink:type="extended" xlink:title="99940701 - Disclosure - ACCOUNTS PAYABLE, ACCRUED LIABILITIES, AND RELATED PARTY PAYABLE (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="mrkr-20241231.xsd#mrkr_AccountsPayableAndAccruedLiabilitiesIncludingRelatedPartyPayableCurrent" xlink:label="mrkr_AccountsPayableAndAccruedLiabilitiesIncludingRelatedPartyPayableCurrent" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent_638790200893154946" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="mrkr_AccountsPayableAndAccruedLiabilitiesIncludingRelatedPartyPayableCurrent" xlink:to="us-gaap_OtherAccruedLiabilitiesCurrent_638790200893154946" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:label="us-gaap_AccruedProfessionalFeesCurrent_638790200893164961" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="mrkr_AccountsPayableAndAccruedLiabilitiesIncludingRelatedPartyPayableCurrent" xlink:to="us-gaap_AccruedProfessionalFeesCurrent_638790200893164961" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_638790200893164961" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="mrkr_AccountsPayableAndAccruedLiabilitiesIncludingRelatedPartyPayableCurrent" xlink:to="us-gaap_EmployeeRelatedLiabilitiesCurrent_638790200893164961" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent_638790200893164961" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="mrkr_AccountsPayableAndAccruedLiabilitiesIncludingRelatedPartyPayableCurrent" xlink:to="us-gaap_AccountsPayableCurrent_638790200893164961" order="4" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="us-gaap_OtherLiabilitiesCurrent_638790200893164961" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="mrkr_AccountsPayableAndAccruedLiabilitiesIncludingRelatedPartyPayableCurrent" xlink:to="us-gaap_OtherLiabilitiesCurrent_638790200893164961" order="5" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="mrkr-20241231.xsd#mrkr_TaxFeesPayable" xlink:label="mrkr_TaxFeesPayable_638790200893164961" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="mrkr_AccountsPayableAndAccruedLiabilitiesIncludingRelatedPartyPayableCurrent" xlink:to="mrkr_TaxFeesPayable_638790200893164961" order="6" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.tapimmune.com/role/DisclosureIncomeTaxesSummaryOfEffectsOfTemporaryDifferencesThatGiveRiseToSignificantPortionsOfDeferredTaxAssetsDetails" xlink:type="extended" xlink:title="99941301 - Disclosure - INCOME TAXES - Summary of Effects of Temporary Differences that Give Rise to Significant Portions of the Deferred Tax Assets (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:label="DeferredTaxAssetsLiabilitiesNet" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="us-gaap_DeferredTaxAssetsNet_638790200893174964" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="DeferredTaxAssetsLiabilitiesNet" xlink:to="us-gaap_DeferredTaxAssetsNet_638790200893174964" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="us-gaap_DeferredTaxAssetsGross_638790200893174964" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_DeferredTaxAssetsNet_638790200893174964" xlink:to="us-gaap_DeferredTaxAssetsGross_638790200893174964" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_638790200893174964" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_DeferredTaxAssetsGross_638790200893174964" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_638790200893174964" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="mrkr-20241231.xsd#mrkr_Deferredtaxstockbasedcompensation" xlink:label="mrkr_Deferredtaxstockbasedcompensation_638790200893174964" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_DeferredTaxAssetsGross_638790200893174964" xlink:to="mrkr_Deferredtaxstockbasedcompensation_638790200893174964" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch" xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_638790200893174964" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_DeferredTaxAssetsGross_638790200893174964" xlink:to="us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_638790200893174964" order="3" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetsInProcessResearchAndDevelopment" xlink:label="us-gaap_DeferredTaxAssetsInProcessResearchAndDevelopment_638790200893174964" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_DeferredTaxAssetsGross_638790200893174964" xlink:to="us-gaap_DeferredTaxAssetsInProcessResearchAndDevelopment_638790200893174964" order="4" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_638790200893184963" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_DeferredTaxAssetsNet_638790200893174964" xlink:to="us-gaap_DeferredTaxAssetsValuationAllowance_638790200893184963" order="2" use="optional" weight="-1" priority="2" />
  </calculationLink>
  <calculationLink xlink:role="http://www.tapimmune.com/role/DisclosureIncomeTaxesScheduleOfExpectedTaxExpenseBenefitFromContinuingOperationsDetails" xlink:type="extended" xlink:title="99941303 - Disclosure - INCOME TAXES - Schedule of expected tax expense (benefit) from continuing operations (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="IncomeTaxExpenseBenefit" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_638790200893184963" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_638790200893184963" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_638790200893184963" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_638790200893184963" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate" xlink:label="us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate_638790200893184963" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate_638790200893184963" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="mrkr-20241231.xsd#mrkr_Permanentdifferencesotherpermanentdifferences" xlink:label="mrkr_Permanentdifferencesotherpermanentdifferences_638790200893184963" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="mrkr_Permanentdifferencesotherpermanentdifferences_638790200893184963" order="4" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_638790200893195125" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_638790200893195125" order="5" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="mrkr-20241231.xsd#mrkr_EffectiveIncomeTaxRateReconciliationDeferredTaxTrueUpAdjustmentAmount" xlink:label="mrkr_EffectiveIncomeTaxRateReconciliationDeferredTaxTrueUpAdjustmentAmount_638790200893195125" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="mrkr_EffectiveIncomeTaxRateReconciliationDeferredTaxTrueUpAdjustmentAmount_638790200893195125" order="6" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxReconciliationOtherAdjustments" xlink:label="us-gaap_IncomeTaxReconciliationOtherAdjustments_638790200893195125" />
    <calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxReconciliationOtherAdjustments_638790200893195125" order="7" use="optional" weight="1" />
  </calculationLink>
</link:linkbase>
