ABCB1 and carcinoma: Regarding the drug transporter regulation, it is known that efflux transporters ABCG2 (BCRP) and ABCB1 (P-gp) are induced by TCDD mediated AhR activation in Caco-2 and other human carcinoma cells including HepG2, LS180, LS174T and MCF7 cells (Ebert et al., 2005; Tan et al., 2010).