A. Specific inhibitor for caspase-3, caspase-9 and pancaspase inhibitor reduce ARC/ABT-737 induced apoptosis, while specific inhibitor for caspase-8 demonstrates no reduction in apoptosis detected by immunoblotting for cleaved caspase-3 in SW480 and HepG2 cells. B. Quantitation of apoptotic cells by using in vitro chromatin condensation detection kit. Combination of ARC/ABT-737 enhance fluorescence intensity in SW480 cells, pan-caspase inhibitor, caspase-3 and -9 inhibitors, but not caspase-8 inhibitor lower the fluorescence intensity of SW480 cells (mean ± SD of 3 separate determinations).