MAPT and Alzheimer disease: Accumulation of neurotoxic Aβ plaques and hyperphosphorylation of tau have long been considered the pathological hallmarks that contribute to synaptic disruption and neuronal loss in the brains of AD patients (Skovronsky et al., 2006; Querfurth and LaFerla, 2010; Serrano-Pozo et al., 2011; Krstic and Knuesel, 2013; Amtul, 2016; Harrison and Owen, 2016).