PRNP and Alzheimer disease: Similar to the evolution of PrPC towards PrPSc in PRDs such as kuru, Creutzfeldt-Jakob, GSS, and fatal familial insomnia, all NDG afflictions show misfolding proteins, such as α-synuclein [192], A-β, APP, τ in AD, TDP-43 in ALS, HTT, and the amyloid protein [193].