Tumor cells may display a multidrug resistant phenotype by overexpression ofATP-binding cassette transporters such as multidrug resistance (MDRI) p-glycoprotein,multidrug resistance protein 1 (MRP1), and breast cancer resistance protein (BCRP).Tumor cells can be intrinsically resistant to drugs or they can acquire resistance tostructurally and functionally unrelated drugs on drug exposure. This phenomenon isknown as multidrug resistance (MDR). In human tumor cells, several transporterproteins can be involved in MDR. These proteins, MDR1 P-gp (ABCB1), MRP1(ABCC1), MRP2 (ABCC2), MRP3 (ABCC3), and BCRP (ABCG2), belong to the ABCtransporter family. They act as efflux pumps, which result in decreased intracellularconcentrations of cytotoxic drugs.BCRP is a recently discovered half-transporter that probably acts as a homo- orheterodimer in transporting cytotoxic agents. The transporter molecule is capable oftransporting several anticancer drugs but has thus far been found mainly in MX-resistantcell lines. Alternate Names: Anti-ABC15 antibody, Anti-ABCG 2 antibody, Anti-ABCG2 antibody, Anti-ABCPantibody, Anti-ATP-binding cassette sub-family G member 2 antibody, Anti-BCRP1antibody, Anti-BMDP antibody, Anti-Breast cancer resistance protein antibody,Anti-CDw338 antibody, Anti-CDw338 antigen antibody, Anti-EST157481 antibody,Anti-MGC102821 antibody, Anti-Mitoxantrone resistance associated protein antibody,Anti-MRX antibody, Anti-MXR antibody, Anti-MXR1 antibody, Anti-Placenta-specificATP-binding cassette transporter antibody.