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  <xs:element id="crdf_LessorAreaOfSublease" abstract="false" name="LessorAreaOfSublease" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:areaItemType"/>
  <xs:element id="crdf_EquityIncentivePlan2021Member" abstract="true" name="EquityIncentivePlan2021Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="crdf_ClassOfWarrantOrRightWeightedAverageExercisePriceOfWarrantsOrRights" abstract="false" name="ClassOfWarrantOrRightWeightedAverageExercisePriceOfWarrantsOrRights" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="num:perShareItemType"/>
  <xs:element id="crdf_InducementGrantStockOptionsMember" abstract="true" name="InducementGrantStockOptionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="crdf_ReleaseOfClinicalTrialFundingCommitment" abstract="false" name="ReleaseOfClinicalTrialFundingCommitment" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="crdf_LesseeOperatingLeaseMonthlyRentPayment" abstract="false" name="LesseeOperatingLeaseMonthlyRentPayment" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="crdf_SeriesEConvertiblePreferredStockMember" abstract="true" name="SeriesEConvertiblePreferredStockMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="crdf_StockIssuedDuringPeriodSharesWarrantsExercised" abstract="false" name="StockIssuedDuringPeriodSharesWarrantsExercised" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="crdf_AccruedDirectorFees" abstract="false" name="AccruedDirectorFees" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="crdf_DebtSecuritiesAvailableForSaleNoncurrentAbstract" abstract="true" name="DebtSecuritiesAvailableForSaleNoncurrentAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="crdf_IncreaseDecreaseInOperatingLeaseLiability" abstract="false" name="IncreaseDecreaseInOperatingLeaseLiability" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="crdf_ServiceReceivable" abstract="false" name="ServiceReceivable" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="crdf_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpiredInPeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpiredInPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="crdf_ReleaseOfClinicalTrialFundingCommitmentForServicesReceived" abstract="false" name="ReleaseOfClinicalTrialFundingCommitmentForServicesReceived" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="crdf_FurnitureAndOfficeEquipmentMember" abstract="true" name="FurnitureAndOfficeEquipmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="nonnum:domainItemType"/>
  <xs:element id="crdf_LesseeOperatingLeaseAnnualRentIncreasePercentage" abstract="false" name="LesseeOperatingLeaseAnnualRentIncreasePercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="num:percentItemType"/>
  <xs:element id="crdf_AccruedResearchAgreements" abstract="false" name="AccruedResearchAgreements" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="crdf_ClassOfWarrantOrRightWeightedAverageExercisePriceOfWarrantsOrRightsAbstract" abstract="true" name="ClassOfWarrantOrRightWeightedAverageExercisePriceOfWarrantsOrRightsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="crdf_IncreaseDecreaseInOperatingLeaseRightOfUseAsset" abstract="false" name="IncreaseDecreaseInOperatingLeaseRightOfUseAsset" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="crdf_ClassOfWarrantOrRightTermOfOutstandingWarrantsOrRights" abstract="false" name="ClassOfWarrantOrRightTermOfOutstandingWarrantsOrRights" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
</xs:schema>
