Calcineurin is a Ca(2+) dependent protein phosphatase that is involed in several neuornal functions. Proteins belonging to the RCAN (Regulator of calcineurin) family modulate the activity of Calcineurin through a valine-rich region within their carboxyl tail. RCANs compete with NFATs (Nuclear factor of activated T-cells) for binding to the same docking site in calcineurin, which results in either inhibition or activation of calcineurin activity. Calcipressin-2, also known as RCAN2 and DSCR1L1 (Down syndrome candidate region 1-like 1), is a 197 amino acid protein that is highly expressed in both the cytoplasm and nucleus of neurons and is the only RCAN family member that is found in glial cells. Calcipressin-3, also known as RCAN3 and DSCR1L2 (Down syndrome candidate region 1-like protein 2), is a 241 amino acid protein that potentially is involved in central nervous system development. Calcipressin-3 interacts with cardiac troponin I, suggesting that it may play a role in cardiac contraction events.