XIAP and colonic neoplasm: In colon cancer cells, casticin potentiated the apoptosis induced by TNF-related apoptosis-inducing ligand (TRAIL) through upregulation of death receptor 5 and downregulation of survival proteins, such as survivin, Bcl-xL, Bcl-2, cellular FLICE-like inhibitory protein (cFLIP), and X-linked inhibitor of apoptosis protein (XIAP) [95].