PGP and colorectal carcinoma: Drug transporters of the ABC family are overexpressed in tumours, promoting resistance to chemotherapy drugs.26 MDR1/P-gp is a member of the ABC membrane transporter family that exhibits energy-dependent drug pump activity and can transfer drugs out of cells.27 Studies have shown that inhibition of MDR1/P-gp reverses drug resistance in CRC.28 However, direct treatment strategies for MDR1/P-gp have not proven successful in clinical trials.