The abnormal phosphorylation of tau during AD is either related to an increase in kinase activity (glycogen synthase kinase 3β, cyclin-dependent kinase-5, p42/44 MAP kinase, p38 MAPK, stress-activated protein kinases, mitotic protein kinases) and/or a decrease in phosphatase activity (protein phosphatases 1, 2a, 2b) [48–52]. Here, MAPT is linked to Alzheimer disease.