XIAP and cancer: High levels of c-IAP2 play an important role in the malignant progression of early pancreatic cancers [57]. Survivin inhibits apoptosis through uniting with XIAP to prevent XIAP breakdown by the ubiquitin-proteasome complex together with enhancing its inhibition of caspases, which in turn plays an important role in cancer chemoradiotherapy resistance and unfavorable outcome [58,59].