The neuropathological hallmarks of AD include neuronal loss (Terry et al., 1991) accumulation of extracellular Aβ plaques, and neurofibrillary tangles composed of intracellular aggregates of tau protein (Selkoe, 2001; Schoonenboom et al., 2004; Sobów et al., 2004; Iqbal et al., 2005). The gene discussed is MAPT; the disease is Alzheimer disease.