The reports indicate that CYP1A1 is control by ligand activation of AhR and CYP1B1 is regulated by constitutive AhR signaling [41], [42], Therefore, to confirm transcriptional activity of the AhR signaling pathway, AhR responsive gene, CYP1B1 was measured by qRT-PCR in the androgen sensitive LNCaP cell line as well as the advanced prostate cancer cell lines, DU145, PC3and PC3M. This evidence concerns the gene AHR and prostate cancer.