Notably, given both survivin and antiapoptotic BCL-2 proteins represent two integral branches of pro-survival mechanisms that promote therapeutic resistance of cancer cells, our discovery that Obatoclax downregulates survivin aside from inhibiting anti-apoptotic BCL-2 proteins is clinically attractive regarding the use of Obatoclax to facilitate drug sensitization in cancer cells with inherent or acquired resistance to cancer therapeutics [16,26,39,40]. This evidence concerns the gene BIRC5 and cancer.