MAPT and Alzheimer disease: Neuropathological characteristics of AD are defined by the presence of extracellular aggregation of amyloid-beta (Aβ) protein in the form of senile plaques and perivascular amyloid, as well as neurofibrillary tangles (NFT) and neuropil threads, composed of hyperphosphorylated microtubule associated protein Tau (p-Tau).