We have developed a novel targeted therapeutic for breast cancer, called AMF/PGI-paclitaxel. When AMF/PGI binds to its receptor (gp78/AMFR) it is efficiently and selectively taken up by cancer cells. By linking AMF/PGI to paclitaxel (an anti-cancer drug used clinically for breast cancer treatment) we expect to deliver this chemotherapeutic drug more selectively to breast cancer cells, but not normal body cells. This should increase the efficacy and reduce toxic side effects of breast cancer treatment with paclitaxel.  We will assess whether AMF/PGI-paclitaxel prevents tumor growth, induces tumor regression and prolongs survival in mice bearing human breast tumors. We will also study gp78/AMFR expression and AMF/PGI uptake in freshly isolated human breast cancers. If successful, these studies will suggest that AMF/PGI-paclitaxel is an anti-cancer drug of potential value for treatment of human breast cancer and lead to its development for clinical application.