Institution: | 1Department of Veterinary Surgery, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea.;2Laboratory of Stem Cell and Tumor Biology, Department of Veterinary Public Health, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea.;3College of Veterinary Medicine, Research Institute of Veterinary Medicine, Chungnam National University, Daejeon 305-764, Korea. |