The neuropathological hallmarks of AD are the intracellular aggregation of neurofibrillary tangles (NFTs) containing paired helical filaments (PHFs) consisting of hyperphosphorylated tau protein and the extracellular deposition of senile plaques (SPs) composed of beta-amyloid (Aβ) peptides derived from amyloid precursor protein (APP) (Hardy and Selkoe, 2002; Binder et al., 2005; Goedert and Spillantini, 2006; Roberson and Mucke, 2006; Ballatore et al., 2007; Ittner and Gotz, 2011). The gene discussed is APP; the disease is Alzheimer disease.