E2F1 and hepatocellular carcinoma: Analyses of seven hepatoma cells (Hep G2, Hep 3B, SK-Hep1, Huh 7, PLC/PRF/5, HA 22T, and HCC36) revealed that the mRNA and protein expression patterns of ISX and E2F1 were co-expressed significantly (3.5–9.9-fold) in hepatoma cells (Hep G2, Hep 3B, SK-Hep1, HA 22T, and HCC36) relative to those of benign hepatocytes (Chang normal liver cells, CNL; Figure 1A and 1B).