FACS and immunostaining analysis revealed that different HCC cell lines have different proportions of CD133-positive cells, in the following order: Huh7 (98.2%), Hep3B (97.7%) > PLC/PRF/5 (77.1%) > Huh7.5 (39.0%) (Fig. 2c). This evidence concerns the gene PROM1 and hepatocellular carcinoma.