MAPT and Alzheimer disease: Neurodegeneration in AD has been traditionally associated with the extracellular accumulation of insoluble amyloid-β42 (Aβ) neuritic plaques (Glenner & Wong, 1984; Lemere et al., 1996) along with the intracellular accumulation of abnormally phosphorylated tau (pTau) (Aβ and Tau), which constitute the neurofibrillary tangles (Spires-Jones & Hyman, 2014).