Breast cancer resistance protein (BCRP/ABCG2), multidrug resistance protein 1 (MRP1/ABCC1), and P-gp are the ATP-binding cassette (ABC) transporter family members that carry out drug efflux and their overexpression contributes to the development of chemoresistance in cancer cells [141,142,143]. This evidence concerns the gene ABCB1 and cancer.