CYP2C19 and hepatocellular carcinoma: Our study demonstrated that HLCs express phase I (CYP2B6, CYP2D6, CYP2C9 CYP2C19, CYP1A2 and CYP2E1), phase II drug-metabolizing enzyme (OATP2) and phase III drug transporters (MRP2) at levels comparable to those of primary human hepatocytes, but higher than HepaRG, the hepatocellular carcinoma cell line frequently used in pharmaceutical industry.