The involvement of ER stress in prion diseases was shown by the upregulation of the ER chaperone Grp58/ERp57 (ER protein) in parallel with PrPSc in scarpie-infected mice [152], Grp78/BiP, Grp94, PDIA1 and Grp58/ERp57 in the cortex of patients affected with variant CJD and sporadic CJD [153], and the heat shock protein 70 (HSP70) in CJD patients and scarpie-infected rodents [154,155]. Here, PDIA3 is linked to prion disease.