MAPT and Alzheimer disease: While neuritic plaques (NP) made up of insoluble, aggregated beta-amyloid (Aβ) peptides and neurofibrillary tangles (NFT) consisting of hyperphosphorylated tau proteins are considered the neuropathological hallmarks of AD, Lewy bodies (LB) arising from aggregation of α-synuclein are a distinct neuropathological feature of LBD.