1. Department of Biomedical Science, College of Life Science, CHA University, Seongnam 463-836, Korea.
2. Department of Gastroenterology, Genomic Research Center for Gastroenterology, Ajou University School of Medicine, Suwon 442-749, Korea.
3. Department of Preventive Medicine, Keimyung University School of Medicine, Daegu 700-712, Korea.