MAPT and Alzheimer disease: AD is characterized by a variety of pathological features, including cerebral cortex atrophy, decrease in brain weight [2], loss of locus coeruleus neuromelanin [3], accumulation of extracellular amyloid-β protein (Aβ), and the occurrence of neurofibrillary tangles (NFTs) due to abnormal tau protein hyperphosphorylation [4].