Down-regulation of inhibitor of apoptosis proteins (IAPs) such as baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5, survivin) and X-linked inhibitor of apoptosis protein (XIAP) was observed in Ewing’s sarcoma, osteosarcoma and rhabdomyosarcoma cell lines12–14. This evidence concerns the gene XIAP and osteosarcoma.