Potent induction of hAhR-dependent gene transcription in transgenic mice, transfected mouse hepatocytes, and human hepatoma cells indicates that IR preferentially activates the human AhR [23]; however, the mechanism of ligand-selective activation and whether structural divergence within the ligand binding domain plays a role in regulation of hAhR functionality had not been thoroughly investigated. Here, AHR is linked to hepatocellular carcinoma.