MAPT and Alzheimer disease: Although the etiology of AD remains unclear, a growing body of evidence implicates that the extracellular senile plaques that result from accumulation of β-amyloid (Aβ) and intracellular tau protein tangles are key histopathological hallmarks of Alzheimer’s disease (AD), and that the neurotoxicity of Aβ may play a central role in the pathogenesis of AD [3, 4].