MAPT and Alzheimer disease: The brains of patients suffering AD present the two classical hallmark histopathological lesions already described by Alois Alzheimer over a century ago, the extracellular “senile plaques” consisting of β-amyloid (Aβ) peptide, and intracellular neurofibrillary “tangles” (NFT) made up of hyperphosphorylated tau protein [61].