It may also be possible to design additional artificial yeast prion domains whose aggregation is driven by non-Q/N-rich amyloidogenic proteins such as the Aβ peptide that accumulates in Alzheimer's disease (Koo et al. 1999) or the mammalian prion protein PrP (Cohen and Prusiner 1998). The gene discussed is PRNP; the disease is Alzheimer disease.