Human and mouse primary hepatocytes were treated vehicle DMSO), CITCO (1 μM), TCPOBOP (250 nM), carapin, santonin, or isokobusone (10 μM each) for 24 h. CYP2B6 and Cyp2b10 mRNA expression was measured by real-time PCR analysis. Data were expressed as fold change over the control, normalized to GAPDH expression. *, P < 0.05, vs the vehicle controls of each genotype.