XIAP and renal carcinoma: To determine whether Bcl-2 and XIAP downregulation was a cause or a consequence of caspase activation and apoptosis, we treated A498 renal cancer cells with DMSO, AR-A014418, DEVD-CHO (reversible tetrapeptide inhibitor of caspase-3 and caspase-7) or a combination of AR-A014418 and DEVD-CHO (Figure 4F).