The two major pathological hallmarks of AD are extracellular amyloid plaques composed of insoluble amyloid beta (Aβ) protein, and intra-neuronal neurofibrillary tangles (NFTs) containing hyperphosphorylated tau (Khachaturian, 1985; Joachim et al., 1987; Selkoe et al., 1987; Mirra et al., 1991; Brun and Englund, 2002). The gene discussed is MAPT; the disease is Alzheimer disease.