XIAP, an NFκB-dependent member of the inhibitor of apoptosis (IAP) family, inhibits apoptotic cell death through binding to the executioner caspase-3, −7, and-9, and has been shown to be upregulated in many human tumors.40–42 Conversely, XIAP was shown to enhance NFκB activation constituting a positive feedback loop to prevent apoptosis.9,43,44 Accordingly, co-application of XIAP-inhibiting SMAC mimetics has successfully been used to sensitize different TRAIL-resistant tumor cells45,46 to apoptotic cell death. Here, XIAP is linked to neoplasm.