According to the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer’s Disease and Related Disorders Association criteria (McKhann et al., 1984), the first definition for diagnosis of AD is relied on neuropathological analysis of brain tissue, obtained by biopsy or autopsy, for the accumulation of Aβ peptides and tau protein. The gene discussed is MAPT; the disease is Alzheimer disease.