MAPT and Alzheimer disease: AD is neuropathologically marked by deposition of abnormally folded amyloid-β (Aβ), tau proteins in extracellular amyloid plaques, and intracellular neurofibrillary tangles, which initiate oxidative stress, neuroinflammation, and lipid metabolism dysregulation, resulting in synaptic dysfunction, neurodegeneration, and neuron death in the brain (3,4).