ABCB6 and hepatocellular carcinoma: ABCB6 mRNA levels inversely correlated with the methylation status of a CpG island in the promoter of ABCB6. This inverse correlation has also been observed in the hepatoma cell lines Hep 3B, Hep G2, HLE, HuH-6, HuH-7, and SK-HEP-1.