MAPT and Alzheimer disease: Extracellular senile plaques consisting of amyloid-β (Aβ) peptides (Glenner and Wong, 1984) and intracellular neurofibrillary tangles (NFTs) composed of abnormally hyperphosphorylated tau protein (Grundke-Iqbal et al., 1986) are the two major histopathological hallmarks in AD brains.