ABCB1 and neoplasm: Meantime, the development of MDR is accompanied with the overexpression of ATP-dependent drug-efflux pump, such as p-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), and the breast cancer resistance protein (BCRP), which is thought to be an essential obstacle to reducing intracellular drug accumulation in tumor eradication [5].