PRNP and sporadic Creutzfeldt-Jakob disease: The identification of the same dominant prion strains (M1CJD and V2CJD) in both sCJD and familial E200K gCJD patients provides an indirect argument supporting the hypothesis that somatic mutations in PRNP could be a key driver in the occurrence of sporadic Creutzfeldt-Jakob disease (sCJD).