Detail for ABCB1

Full Name

Multidrug resistance protein 1 (MDR1)

Uniprot ID

Gene Name



Related Disease

  • Acute Lymphoblastic Leukemia [ref.1, 2]
  • Ovarian Cancer [ref.1, 4]
  • Breast Cancer [ref.3, 5]
  • Chronic Myeloid Leukemia [ref.5]
  • Cervical Cancer [ref.5]
  • Multiple Myeloma [ref.6]
  • Kindey Cancer [ref.7]


ABCB1, also known as P-gp, is an important protein of the cell membrane that pumps many foreign substances out of cells. More formally, it is an ATP-dependent efflux pump with broad substrate specificity. It exists in animals, fungi and bacteria and likely evolved as a defense mechanism against harmful substances.
ABCB1 is extensively distributed and expressed in the intestinal epithelium where it pumps xenobiotics (such as toxins or drugs) back into the intestinal lumen, in liver cells where it pumps them into bile ducts, in the cells of the proximal tubule of the kidney where it pumps them into urine-conducting ducts, and in the capillary endothelial cells composing the blood–brain barrier and blood-testis barrier, where it pumps them back into the capillaries. Some cancer cells also express large amounts of P-gp, which renders these cancers multi-drug resistant.


  • [1] The cancer stem cell selective inhibitor salinomycin is a p-glycoprotein inhibitor.
    Riccioni, R., et al. (2010). Blood Cells Mol Dis 45(1): 86-92.. [ 20444629 ]
  • [2] Salinomycin induces apoptosis and overcomes apoptosis resistance in human cancer cells.
    Fuchs, D., et al. (2009). Biochem Biophys Res Commun 390(3): 743-749.. [ 19835841 ]
  • [3] Effects of stealth liposomal daunorubicin plus tamoxifen on the breast cancer and cancer stem cells.
    Guo, J., et al. (2010). J Pharm Pharm Sci 13(2): 136-151.. [ 20816001 ]
  • [4] Reversing paclitaxel resistance in ovarian cancer cells via inhibition of the ABCB1 expressing side population.
    Eyre, R., et al. (2014). Tumor Biology, 2014: 1-14.. [ 24993095 ]
  • [5] Dofequidar fumarate sensitizes cancer stem-like side population cells to chemotherapeutic drugs by inhibiting ABCG2/BCRP-mediated drug export.
    Katayama, R., et al. (2009). Cancer Sci 100(11): 2060-2068.. [ 19673889 ]
  • [6] Identification of an ABCB1 (P-glycoprotein)-positive carfilzomib-resistant myeloma subpopulation by the pluripotent stem cell fluorescent dye CDy1.
    Hawley, T. S., et al. (2013). Am J Hematol 88(4): 265-272.. [ 23475625 ]
  • [7] Hedgehog pathway inhibitor HhAntag691 is a potent inhibitor of ABCG2/BCRP and ABCB1/Pgp.
    Zhang, Y., et al. (2009). Neoplasia 11(1): 96-101.. [ 19107236 ]

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