In a clinical correlation study, 47 advanced HCC patients were given a single oral administration of sorafenib; plasma sorafenib levels were determined 3 h later and correlated with polymorphisms in ABCG2 and ATP binding cassette subfamily B member 1 (ABCB1), also known as P-glycoprotein (pgp). This evidence concerns the gene ABCG2 and hepatocellular carcinoma.