Inhibits calcineurin-dependent transcriptional responses by binding to the catalytic domain of calcineurin A (PubMed:12809556). Could play a role during central nervous system development (By similarity). Interacts with RAF1 (PubMed:15935327). Interacts with PPP3CA and PPP3R1 (PubMed:12809556). Highly expressed heart, brain and skeletal muscle. Also expressed in all other tissues. By calcium. Phosphorylation increases its ability to inhibit calcineurin and decreases protein half-life. Belongs to the RCAN family.