MAPT and Alzheimer disease: Alzheimer's disease (AD) is an age‐related, progressive neurodegenerative disease which pathologically characterized by the presence of extracellular amyloid‐β (Aβ)‐containing senile plaques and intracellular hyperphosphorylated tau‐containing neurofibrillary tangles, neuroinflammation, synaptic loss and neuronal death, neocortical atrophy and the progressive deterioration of cognitive function(Yankner & Lu, 2009; Crews & Masliah, 2010; Keskin et al., 2017; Long & Holtzman, 2019).