An antibody having an antigen binding region capable of binding an epitope located in an extracellular portion of MRP3 and methods of utilizing same are provided. In particular, the invention provides antibodies targeted at a MRP3 antigen present on cells expressing MRP3 and methods useful in detecting or targeting cells expression the MRP3 antigen, as well as kits, nucleic acids, polypeptides, and cells for providing the antibodies.