MAPT and Alzheimer disease: The pathological features of AD include the progressive accumulation of parenchymal senile plaques consisting of amyloid-β (Aβ) protein and intracellular neurofibrillary tangles (NFTs) composed of abnormal phosphorylated tau, which induce chronic gliosis primarily in cognitive brain areas, and subsequently lead to synaptic damage, cognitive impairment, and neurodegeneration [1–3].