AD is a neurodegenerative disorder characterized by two important neuropathological features: extracellular senile plaques—which are mainly composed of β-amyloid (Aβ) deposits, and intracellular neurofibrillary tangles (NFT)—consisting of bundles of paired helical filaments (PHF), the main component of which is a pathologically hyperphosphorylated tau protein (hptau) [10]. The gene discussed is MAPT; the disease is Alzheimer disease.