MAPT and Alzheimer disease: Abnormal phosphorylation of tau is known to be implicated in the pathogenesis of diverse neurodegenerative diseases, such as AD, PD, dementia with Lewy bodies (DLB), Pick's disease, progressive supranuclear palsy (PSP), frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), and frontotemporal lobar degeneration (FTLD).