1. Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Korea.
2. Department of Pathobiology, Small Animal Tumor Diagnostic Center, College of Veterinary Medicine, Konkuk University, Seoul 143-701, Korea.
3. Department of Cell and Developmental Biology, DRI and Brain Korea 21 Program, School of Dentistry, Seoul National University, Seoul 110-749, Korea.