PPP3CA(aka Calcineurin A) is a major soluble calmodulin binding protein in the brain and a Ca2+/calmodulin dependent serine/threonine protein phosphatase, with a relatively limited substrate specificity. PPP3CA activates the T cells of the immune system and can be blocked by drugs. PPP3CA activates NFATc(a transcription factor) by dephosphorylating it. The activated NFATc is subsequently translocated into the nucleus, where it upregulates the expression of interleukin 2.