MAPT and Alzheimer disease: Once hyperphosphorylated, tau loses its ability to bind microtubules for cytoskeletal stability, forming intracellular neurofibrillary tangles (NFTs), which disrupt neuronal structure and function and contribute to the pathogenesis of AD, PD, VD, and other dementia subtypes (Sun et al., 2021; Li C. et al., 2024; Pan et al., 2022).