The mouse hepatoma cell line Hepa1c1c7 (Hepa-1), in which CYP1A1 is highly inducible, is commonly used as a model system to study the regulation of CYP1A1 and other AhR-regulated genes (Miller, Israel et al. 1983; Whitlock and Galeazzi 1984). Here, AHR is linked to hepatocellular carcinoma.