AT-101 inhibited anti-apoptotic Bcl-2 and Bcl-xL, upregulated BH3 protein (PUMA, NOXA), downregulated X-linked inhibitor of apoptosis protein (XIAP), released apoptogenic Smac, and activated Akt/p53 pathway and SAPK/(c-Jun N-terminal kinase) pathway to induce apoptosis in cancer cells [154]. Here, XIAP is linked to cancer.