1 Division of Gastroenterology and Hepatology, Department of Internal Medicine, Korea University College of Medicine, Seoul, 02841, Republic of Korea.
2 Division of Gastroenterology and Hepatology, Department of Internal Medicine, Korea University College of Medicine, Seoul, 02841, Republic of Korea. mdkorea@gmail.com.
3 Department of Biosystems & Biomaterials Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea.