MAPT and Alzheimer disease: AD is characterized by the presence of extracellular deposits of β-amyloid protein aggregates (Aβ), forming amyloid plaques, and by the presence of intracellular neurofibrillary tangles containing hyperphosphorylated tau protein (Pooler et al., 2014; Spires-Jones and Hyman, 2014; Liu et al., 2019; Long and Holtzman, 2019; Knopman et al., 2021).