Dr. Ko is a pediatric gastroenterologist with a special interest in the genetic study of pediatric gastrointestinal and hepatic disease. His current status is an associate professor of Department of Pediatrics. He has authored over 60 scientific publications including epidemiology and treatment of hepatitis B infection in children and analysis of H. pylori genotype in Korea. He also published mutation studies of glycogen storage disease, Alagille syndrome and neonatal cholestasis. His basic research topic is the role of probiotics in the intestinal epithelial cell. He is working on management of fatty liver disease, obesity and undernutrition in children.