Histopathologically, AD is characterized by two major lesions: amyloid as diffuse and neuritic plaques composed of amyloid β (Aβ) peptide, and neurofibrillary tangles (NFTs) composed of abnormally hyperphosphorylated tau protein (Glenner and Wong, 1984; Grundke-Iqbal et al., 1986a,b). The gene discussed is MAPT; the disease is Alzheimer disease.