MAPT and Alzheimer disease: Among these pathways, the PI3K/AKT/GSK-3β pathway is a crucial pathway that induces Tau hyperphosphorylation in AD; in addition, aberrant Tau hyperphosphorylation is linked to glycogen synthase kinase-3β (GSK-3β), cell cycle protein-dependent kinase 5 (CDK5), and p38 mitogen-activated protein kinase (p38-MAPK)(Hu et al., 2013; Wu et al., 2008).