CASP9 and hepatocellular carcinoma: Interestingly, a decreased expression of the cleaved caspases (-3,-9 and -8) in HCC SK-Hep1 cells by HIF-1α expression was increased by the blocking of IL-6 (Figs. 3A and 3C), but wasn’t significant in cleaved caspase-9 (Fig. 3D).