PRNP and variant Creutzfeldt-Jakob disease: For example, in vitro, human sCJD prions (subtypes 129MM1 and MM2) most efficiently seed unglycosylated PrPC substrates, whereas variant CJD (vCJD) prions preferentially seed glycosylated PrPC substrates [24], illustrating the profound effect of the PrPSc fold on PrPC glycoform recruitment.