1. Department of Clinical Cancer Prevention (C.W., J.A.M., A.M., P.H.B.), The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030;
2. Division of Molecular and Cellular Oncology (K.F., M.B.), Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115;
3. Department of Biology (K.F.), Boston College, Chestnut Hill, Massachusetts 02467;
4. Breast Center (H.K.), Baylor College of Medicine, Houston, Texas 77030