1. Department of Biomedical Science, Graduate School, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea.
2. Department of Anatomy, Graduate School, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea.
3. Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, Korea.
4. Bioindustry Research Center, Korea Research Institute Bioscience and Biotechnology, Daejeon 305-806, Korea.
5. Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea.
6. Department of Biochemistry, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea.