CIAP2 is an apoptotic suppressor. Apoptosis is triggered by a variety of stimuli including members of the TNF family and can be prevented by the inhibitor of apoptosis (IAP) proteins. IAP proteins form a conserved gene family that binds to and inhibits cell death proteases. The two isoforms of cIAP (cIAP1 and cIAP2) are structurally related to XIAP, containing 3 baculoviral IAP repeat (BIR) motifs that are essential and sufficient for the binding and inhibition of caspases-3, -7. The cIAPs can associate with the death receptor TNF-R2, and mediate the ubiquitinization of TRAF2 following the binding of TNF alpha by its receptor. Omi, a negative regulator of cIAP, inhibits its activity by catalytically cleaving cIAP. Another negative regulator, Smac/DIABLO, acts by enhancing the autoubiquitization activity of cIAP.Synonyms: API2, Apoptosis inhibitor 2, Baculoviral IAP repeat-containing protein 3, C-IAP2, HIAP-1, IAP homolog C, Inhibitor of apoptosis protein 1, MIHC, RING finger protein 49, RNF49, TNFR2-TRAF-signaling complex protein 1, cIAP2