While it has been proposed that iPrPC is involved in prion and Alzheimer diseases and in the long-term memory storage according to our recent findings [31-34], new insights into the mechanisms underlying the spontaneous formation of PrP aggregates obtained with cell models would be significant in enhancing our understanding of not only prion diseases but also other diseases involving protein misfolding. Here, PRNP is linked to early-onset autosomal dominant Alzheimer disease.