MAPT and Alzheimer disease: Numerous studies available in literature to understand the pathogenesis of AD, suggest that multiple factors such as low levels of acetylcholine, mitochondrial dysfunction, β-amyloid (Aβ) deposits, tau-protein aggregation, oxidative stress, inflammation, and dyshomeostasis of biometals might be playing a crucial role in the pathogenesis of AD (Zhang, 2005; Mandel et al., 2007; Henry et al., 2010; DeToma et al., 2012; Kotler et al., 2014; Pfaender and Grabrucker, 2014).