I was born at Pusan in Republic of Korea. I graduated from Pusan National University School of Medicine in 1993, and then I spent the internship and resident period at the Pusan National University Hospital. After my duty, military service for 3 years, I spent a fellowship period in the Division of Gastroenterology and Hepatology at Pusan National University Hospital during 2001-2003, and then I became an assistant professor. I went abroad two times for studying endoscopic ultrasonography and gastroesophageal reflux disease: Kitasato University in 2005 and University of Washington Harborview Medical Center in 2014-2015. At now, I am a full professor in the Department of Internal Medicine of Pusan National University School of Medicine. My interests are gastric cancer, esophageal cancer, therapeutic endoscopy, endoscopic ultrasonography and image analysis.