Other studies [48] showed that the PrP178–193 peptide has both structural and bioactive properties in common with the amyloidogenic Alzheimer's disease Aβ(25–35) peptide and that the second putative helical region of PrP could be involved in modulation of Cu (II)-mediatedtoxicity in neurons during prion disease. Here, PRNP is linked to early-onset autosomal dominant Alzheimer disease.