Treatment resistance is a hallmark of cancer cells that develop strategies to bypass cell death.5 Inhibitor of apoptosis proteins (IAPs) are a well-conserved family of eight proteins including cIAP1 (cellular inhibitor of apoptosis protein-1), cIAP2 (cellular inhibitor of apoptosis protein-2), XIAP (X-linked inhibitor of apoptosis protein) and ML-IAP (melanoma inhibitor of apoptosis protein), often expressed in many human cancers.6 IAPs are anti-apoptotic proteins contributing to treatment resistance by inhibiting caspase activation. This evidence concerns the gene XIAP and cancer.