1. Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul 110-744, Republic of Korea
2. Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
3. Department of Obstetrics and Gynecology, School of Medicine, Keio University, Tokyo 160-8582, Japan
4. Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
5. Department of Obstetrics and Gynecology and Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada K1Y 4E9