CDK5 and Alzheimer disease: As revealed for AD, glycogen synthase kinase 3 beta (GSK3β), Cdk5 and p38 MAPK are the major Ser/Thr kinases involved in Tau phosphorylation, with DYRK1A and microtubule affinity-regulating kinase 4 (MARK4) having only a few targets, as summarized in the following list: GSK3β (43 Ser, Thr sites), Cdk5 (13 Ser, Thr), p38 MAPK (19 Ser, Thr), DYRK1A (3 Ser, Thr) and MARK4 (2 Ser, Thr) [79,82,83].