BCL2 and hepatocellular carcinoma: In a study conducted in 2012, Chen et al[53] used a second mitochondrial-derived activator of caspases (SMAC) mimetic, LCL161, on four different hepatocellular carcinoma (HCC) cell lines, namely PLC5, Hep3B, Huh-7, and SK-Hep1, and found that LCL161 showed differential effects on apoptosis in these cells; furthermore, the sensitivity of HCC cells to LCL161 depended on the endogenous levels of BCL-2; sensitive Hep3B and PLC5 cells, expressing lower levels of BCL-2, undergo cytotoxicity and apoptosis, whereas resistant SK-Hep1 and Huh-7 cells, expressing higher levels of BCL-2, do not.