To further clarify the regulatory mechanism of IVIG-caused apoptosis in hepatocellular carcinoma cells, we evaluated the expression of two vital members from the Bcl-2 family, Bcl-2 and Bax, and the executioner caspase, cleaved caspase-3, at the protein level by Western blotting. The gene discussed is CASP3; the disease is hepatocellular carcinoma.