, Xenopus/Amphibian,-linked inhibitor of apoptosis protein (, Xenopus/Amphibian,IAP) is an apoptotic suppressor. , Xenopus/Amphibian,IAP has E3 ubiquitin-protein ligase activity. , Xenopus/Amphibian,IAP mediates the proteasomal degradation of target proteins, such as caspase-3, SMAC or AIFM1. , Xenopus/Amphibian,IAP is an inhibitor of caspase-3, -7 and -9. , Xenopus/Amphibian,IAP mediates activation of MAP3K7/TAK1, leading to the activation of NF-kappa-B. Defects in , Xenopus/Amphibian,IAP are the cause of lymphoproliferative syndrome , Xenopus/Amphibian,-linked type 2 (, Xenopus/Amphibian,LP2). , Xenopus/Amphibian,LP is a rare immunodeficiency characterized by e, Xenopus/Amphibian,treme susceptibility to infection with Epstein-Barr virus (EBV).