In human hepatoma cells, PPARα also regulates hepatic genes, including multidrug resistance protein 1 (MDR1), multidrug resistance-associated protein 2 (MRP2/ABCC2), MRP3, and MRP4, which encode ABC transporters known to play a vital role in effluxing bile acids and therapeutic drugs [25–27]. This evidence concerns the gene ABCB1 and hepatocellular carcinoma.