PRNP and Alzheimer disease: Dohler et al. (2014) demonstrated that optimal binding to PrPC occurs in the insoluble fraction of Aβ. Their data show that Aβ is present as insoluble oligomers in all tested high molecular weight fractions. Another study using AD and healthy brains also showed the preferential binding of high molecular weight Aβ42 assemblies to PrPC, which occurs mainly in the insoluble fraction of Aβ, in AD (Zou et al., 2011).