Multi-drug resistance (MDR)
Multi-drug resistance is a condition where cancer cells are resistant to chemotherapy drugs due to the presence on a drug eflux pump called the p-glycoprotein that actively pumps out drugs from the cell. P-glycoprotein in normal gut epithelial cells help to expell toxic substances in the food we eat, but this is up-regulated in cancer cells. The p-glycoprotein is part of the ABC transporter superfamily. Also see Antibiotic Resistance.