She was a member of the faculty at the University of Illinois from 1981-1989, and came to Rush in 1989, where she also serves as Director of the Comprehensive Breast Center. Dr. Cobleigh graduated from Rush Medical College. She completed her internship and residency at Rush University Medical Center and her Medical Oncology Fellowship at Indiana University. Dr. Cobleigh's national service includes a variety of ASCO commitments including: Program Committee (Breast Cancer), the Patient Advocacy Committee, the Health Services Research Committee and the Editorial Board of the Journal of Clinical Oncology. In addition, she has been a member of study sections of the NIH, the Medical Advisory Board of the Y-Me National Breast Cancer Organization, the Breast Cancer Core Committee of the ECOG, and the Board of Directors of the NSABP.

With a primary clinical and research interest of breast cancer, she has published articles on chemotherapy, endocrine therapy, retinoid therapy, monoclonal antibody therapy, antiangiogenesis agents, antisense strategies, and tumor vaccines for that disease. A major focus of her work is bridging the gap between the clinic and the bench in understanding the biology of breast disease and the mechanisms of resistance and sensitivity to targeted therapies.