PRNP and Alzheimer disease: Examples of possible such non-AD biomarkers are TAR DNA-binding protein 43 (TDP-43) (61–63), TPD-43 phosphorylated at S409 (pTDP-43) (63), and progranulin (64–66) for FTD, α-synuclein (67–71) and neurosin (72) for DLB, metalloproteinases-9 for VaD (73, 74), and total CSF prion protein for CJD (75).