sentences:  Survivin, like the others, was discovered by its structural homology to IAP family of proteins in human B-cell lymphoma.The human IAPs, XIAP, c-IAPl, C-IAP2 have been shown to bind to caspase-3 and -7, which are the effector caspases in the signaling pathway of apoptosis.It is not known with absolute certainty though, how the IAPs inhibit apoptosis mechanistically at the molecular level.