CASP9 and neoplasm: Western blot analysis suggested that chloramphenicol (≥ 50 μg/mL) increased the abundance of Cytc, cleaved caspase 9, and cleaved caspase 3 in tumor cells, and that this effect on the caspases was blocked by 25 μM Z-VAD-FMK, a nonspecific caspase inhibitor (Figure 4C).