1. Department of Obstetrics and Gynecology, Oncology Research Institute, Greenville Hospital System, Greenville, South Carolina 29605
2. Department of Dermatology, University of North Carolina, Chapel Hill, North Carolina 27599
3. Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710
4. Laboratory for Reproductive Biology, University of North Carolina, Chapel Hill, North Carolina 27599
5. Departamento de Fisiologia Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain
6. University Medical Group, and Developmental Biology Laboratory, Oncology Research Institute, Greenville Hospital System, Greenville, South Carolina 29605