MAPT and Alzheimer disease: Alzheimer's disease (AD) is a progressive neurodegenerative disorder that is characterized by symptoms like memory impairment, cognitive dysfunction, perception disturbance and language problems, and by neuropathological alterations including excess deposition of extracellular beta-amyloid peptides (Aβ), aggregation and accumulation of intracellular hyperphosphorylated tau protein, and neuronal loss in some areas of the brain (Dos Santos Picanco et al., 2018; Veitch et al., 2019).