1. Department of Obstetrics, Gynecology, and Reproductive Sciences (C.L.C.), University of Maryland School of Medicine, Baltimore, Maryland 21210
2. Department of Animal Science (K.E.L., U.M.), Michigan State University, East Lansing, Michigan 48824
3. The Fels Institute for Cancer Research and Molecular Biology and Department of Biochemistry (N.R.M.), Temple University School of Medicine, Philadelphia, Pennsylvania 19140
4. California National Primate Research Center and Department of Obstetrics and Gynecology (C.A.V.), University of California, Davis, California 95616