Various processes and pathways are observed dysfunction in AD brain network, which involve Aβ accumulation and aggregation, tau hyperphosphorylation, cholinergic hypofunction, metal dyshomeostasis, glutamate excitotoxicity, cell cycle dysregulation and neuroinflammation, as well as disturbance of mitochondrial function and oxidative stress induced neurotoxicity. Here, MAPT is linked to Alzheimer disease.