XIAP and cancer: Up regulation of several IAPs like NAIP (BIRC1), X-linked IAP (XIAP, BIRC4), Survivin (BIRC5), c-IAP1 (BIRC2), c-IAP2 (BIRC3), Apollon (BRUCE, BIRC6), Livin/MLIAP (BIRC7) and IAP-like protein 2 (BIRC8) have been reported in several cancer cells as well as in serum from cancer patients [10, 11].