PRNP and early-onset autosomal dominant Alzheimer disease: For example, Aβ, α-synuclein, and the prion protein (PrP) form amyloid deposits in the brain, and are associated with Alzheimer’s Disease (AD), Parkinson’s Disease (PD), and Creutzfeldt–Jakob Disease (CJD), respectively, while amyloid formation of islet amyloid polypeptide (IAPP) in the pancreas is associated with type 2 diabetes (T2D) [9].