MAPT and Alzheimer disease: Despite its multifactorial etiopathogenesis, two pathological hallmarks in AD brain are believed to contribute to the progression of the disease [4], i.e., neurofibrillary tangles (NFTs) principally consisting of hyperphosphorylated tau protein, and extracellular amyloid plaques mainly composed of aggregated beta-amyloid (Aβ) peptide.