PRNP and Alzheimer disease: Examples of aggregation-prone proteins in neurodegenerative disorders include alpha-synuclein (α-syn) in synucleinopathies such as PD and multiple system atrophy (MSA); amyloid-beta (Aβ) and hyper-phosphorylated tau in AD; prion protein (PrP) in Creutzfeldt–Jakob disease; polyglutamine-expanded huntingtin in HD; polyglutamine-expanded androgen receptor (ARpolyQ) in SBMA; TAR-DNA-binding protein of 43 kDa (TDP-43) in ALS/FTD, as well as TDP-43, and Cu/Zn superoxide dismutase (SOD), fused in sarcoma (FUS), among others, in ALS [10,25].