AHR and colonic neoplasm: As another example, 3-methylcholanthrene (3MC) upregulates ABCG2 expression in colon cancer LS174T cells via the activation of AHR which binds to the AHR response element 5 within ABCG2 promoter region and thus activate the transcription of ABCG2 (Tompkins et al., 2010).