Apoptosis, or programmed cell death, is related to many diseases, such as cancer. Apoptosis is triggered by a variety of stimuli including members in 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 c-IAP (c-IAP1 and c-IAP2) are structurally related to XIAP, containing 3 baculoviral IAP repeat (BIR) motifs that are essential and sufficient for the binding and inhibition of caspases