Ca2+/calmodulin-dependent protein kinases II or CaM kinases II are serine/threonine-specific protein kinases that are regulated by the Ca2+/calmodulin complex. CaMKII is involved in many signaling cascades and is thought to be an important mediator of learning and memory. CaMKII is also necessary for Ca2+ homeostasis and reuptake in cardiomyocytes, chloride transport in epithelia, positive T-cell selection, and CD8 T-cell activation.