When HCC patients were divided according to the Edmondson Steiner HCC grading system, the expression of ABCG2 was found to be higher in HCC with poorly differentiated HCC G3/G4 (n=6) as compared to well- and moderately-differentiated HCC G1/G2 (n=13) (p<0.05). This evidence concerns the gene ABCG2 and hepatocellular carcinoma.