Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, 151-742, Korea.|Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, 151-742, Korea.|Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, 151-742, Korea.|Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, 151-742, Korea.