MAPT and Alzheimer disease: Huge data reported in literature suggest that multiple factors such as amyloid-β (Aβ) assemblies, tau-protein aggregation and hyperphosphorylation, low levels of acetylcholine (ACh), mitochondrial dysfunction, oxidative stress, inflammation and dyshomeostasis of biometals might be actively involved in AD (Querfurth and LaFerla, 2010; Pfaender and Grabrucker, 2014; Stancu et al., 2014; Selkoe and Hardy, 2016; Wilkins and Swerdlow, 2016; Hardy, 2017).