Thus, XIAP and/or cIAPs protect melanoma cells from DL-induced apoptosis (CD95L) as also found in breast42 or pancreatic cancer.43 XIAP/cIAPs suppression by macrocyclic XIAP antagonists in melanoma and breast cancer support cell death induction and tumour growth inhibition in vivo,44 indicative of the indispensable protective role of IAPs in many cancer entities. Here, XIAP is linked to breast cancer.