MAPT and Alzheimer disease: Alzheimer’s disease (AD) is the most common neurodegenerative disorder and type of dementia, and it is characterized by the deposition of neurotoxic protein aggregates, namely, extracellular amyloid-β (Aβ) in the form of plaques and intracellular hyperphosphorylated tau in the form of neurofibrillary tangles (NFTs), associated with neuroinflammation and neurodegeneration (Figure 2e,f) [114,115].