MAPT and Alzheimer disease: The major neuropathological hallmarks of AD include neuronal and synaptic loss, and proteinaceous aggregates in the form of senile plaques, composed of amyloid‐β (Aβ) peptides as well as neurofibrillary tangles, consisting of hyperphosphorylated tau (p‐tau) in the brain (Overk & Masliah, 2014; Ramirez et al., 2017).