MAPK8 and Alzheimer disease: We found that in the AD P-tau-injected hippocampi of Tg/htau and Tau−/− mice, levels of PDPKs, Cdk5, inactive form of GSK-3β (phosphorylated GSK-3β at Ser9), Dyrk1A, active form of Erk (phosphorylated Erk at Thr202/Tyr204), and active form of Jnk/SAPK (phosphorylated Jnk/SAPK at Thr183/Tyr185), were not altered as compared with that in the saline-injected hippocampus (Figures 7A,B), suggesting that they may not contribute to AD P-tau-induced tau hyperphosphorylation.