AD is clinically characterized by progressive decline in memory (Hardy, 2006), and histologically characterized by neuronal loss (Gunawardena & Goldstein, 2001), dystrophic neurites (Glenner, 1989), neurofibrillary tangles of hyperphosphorylated Tau (Goedert, Wischik, Wischik, Crowther, Walker, & Klug, 1988), and extracellular amyloid plaques (Selkoe, Abraham, Abraham, Podlisny, & Duffy, 1986). The gene discussed is MAPT; the disease is Alzheimer disease.