MAPT and Alzheimer disease: The neuropathological features of AD include neuritic plaques (extracellular deposits of the beta-amyloid protein, Aβ), neurofibrillary tangles (resulting from hyperphosphorylation of the tau protein), a predominantly cholinergic synaptic decrease, and the presence of inflammatory markers, all these characteristics together trigger the neurodegenerative process and cognitive deterioration.