AHR and breast cancer: Hence, prominent ligands of the AhR behave also as inducers of CYP 1A1 activity, such as 2,3,7,8–tetrachlorodibenzo-p-dioxin (TCDD) and benzo[a]pyrene (B[a]P), which are suggested to be involved in increased breast cancer risk [36,37,38,39,40].