CBS and hepatocellular carcinoma: Compared to normal hepatocyte line L02, human hepatocellular carcinoma cell line (e.g. PLC/PRF/5) shows significantly higher H2S and increased overexpression levels of CSE and CBS [61, 62], at low concentrations, 25-100 μM NaHS promotes the proliferation of hepatocellular carcinoma (HCC) cell lines, while at high concentrations, 800–1000 μM NaHS induces HCC apoptosis.