APP and Alzheimer disease: In recent decades, the pathogenic mechanisms of AD have been obscure, but the most recognized mechanism is that APP is initially cleaved by β-secretase and subsequently cleaved by γ-secretase generating Aβ oligomers (Mangialasche et al., 2010; Schonrock et al., 2012), which strongly induce neuronal toxicity, synaptic failure, and memory loss in cell or animal models of AD (Selkoe, 2002; Haass and Selkoe, 2007).