BIRC2 and melanoma: Since then, eight IAP proteins have been identified in humans: NIAP, also called neuronal apoptosis inhibitory protein or BIRC1; c-IAP1, also called cellular IAP1 or BIRC2; c-IAP2, also called cellular IAP2 or BIRC3; XIAP, also called X chromosome–linked IAP or BIRC4; survivin, also called BIRC5; BIRC6, also called ubiquitin-conjugating BIR domain enzyme apollon; livin, also called melanoma IAP, ML-IAP, or BIRC7; and ILP2, also called IAP-like protein 2 or BIRC8 [47,50].