1. Department of Molecular and Cellular Biology (V.B., M.A.M., D.P.E.), Baylor College of Medicine, Houston, Texas 77030;
2. Garvan Institute of Medical Research (E.M.), Cancer Research Program, Darlinghurst, New South Wales 2010, Australia;
3. University of Colorado Health Sciences Center Cancer Center (L.S.), Aurora, Colorado 80045;
4. Wyeth Womens Health Research Institute (B.J.C.), Collegeville, Pennsylvania 19426