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]. The gene discussed is ABCC2; the disease is hepatocellular carcinoma.