Our laboratory is interested in understanding the contribution of insulin-like growth factor (IGF) action to the breast cancer malignant phenotype. We have shown that IGF-I can stimulate cell growth, enhance survival, and stimulate motility and adhesion. Activation of specific substrates, insulin receptor substrate-1 (IRS-1) and IRS-2 are associated with either cell proliferation or cell motility. A major focus of the laboratory is to elucidate the signals downstream of these two adaptor proteins that account for the observed phenotype. In breast cancer, development of therapeutics designed to target specific growth regulatory molecules has proven to be remarkably successful in the clinic. Since the IGFs regulate several important breast cancer phenotypes, the second focus of the laboratory is to develop anti-IGF strategies that have potential as cancer therapeutics. Our long-term goal is to improve breast cancer treatment by understanding and targeting the key components of the IGF system.