ABCB1 and cancer: Among them, ABC subfamily B member 1 (ABCB1)/P-glycoprotein (MDR1) has been implicated as the major efflux transporter responsible for the resistance of cancer cells to many anticancer agents such as cisplatin, docetaxel, anthracyclines (doxorubicin, epirubicin), etoposide, irinotecan, methotrexate, paclitaxel, and vincristine [5, 6].