MAPT and Alzheimer disease: Beyond the well‐established pathological hallmarks of AD—extracellular amyloid‐β (Aβ) plaques, and intracellular neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau—researchers have increasingly appreciated the contribution of early neuroinflammation, mediated by microglia and astrocytes, in AD pathology.2