MAPT and Alzheimer disease: Two main neuropathological features characterize AD: the accumulation of aggregates of amyloid β (Aβ) peptides in extracellular brain parenchyma and in the perivascular areas (senile plaques and amyloid angiopathy, respectively) and intracellular fibrils of hyper-phosphorylated tau (the neurofibrillary tangles) [1].