MAPT and Alzheimer disease: Alzheimer’s disease (AD) is the most common age-related neurodegenerative disorder characterized by abnormal accumulation and deposition of various amyloid-β (Aβ) peptides derived from amyloid-β precursor protein (APP), formation of neurofibrillary tangles containing hyperphosphorylated tau, synaptic dysfunction, neuroinflammation, neuronal death, and cognitive decline (Crews and Masliah, 2010; Huang and Mucke, 2012; Guerreiro and Bras, 2015; Kocahan and Dogan, 2017; DeTure and Dickson, 2019).