The marked decrease in PLTP−/− mouse survival in the Western diet-fed group compared with the chow diet-fed group suggests that non-HDL-containing lipoproteins play a critical role in prion transport, which is in good agreement with the data reported by Safar et al. (14) showing that PrPSc in sporadic CJD patients associates with VLDLs and LDLs. This evidence concerns the gene PLTP and sporadic Creutzfeldt-Jakob disease.