Recently a study to assess the potential of mercury to induce early and late-stage apoptosis in human liver carcinoma (HepG2) cells using annexin-V and caspase 3 assays and flow cytometric analysis to determine the extent of phosphatidylserine externalization and caspase 3 activation in HepG2 cells treated with subacute doses of mercury (LD50  3.5 ± 0.6 μg/mL for mercury in HepG2 cells) for 10 to 48 h established a dose response relationship between mercury exposure and the degree of early and late-stage apoptosis in HepG2 cells. This evidence concerns the gene CASP3 and hepatocellular carcinoma.