Although the primary risk factor is aging, at the molecular level, AD has been associated with extracellular accumulation of beta-amyloid peptide (Aβ) and intracellular neurofibrillary tangles of hyperphosphorylated Tau protein, loss of synaptic connections, and oxidative stress increase leading to neuronal death (Querfurth and LaFerla, 2010). The gene discussed is APP; the disease is Alzheimer disease.