1. Division of Gastroenterology, Department of Internal MedicineHallym University Dongtan Sacred Heart Hospital, Hallym University College of Medicine Gyeonggi‐do Korea
2. Department of Gastroenterology, Asan Medical CenterUniversity of Ulsan College of Medicine Seoul Korea
3. Department of PathologyHallym University Dongtan Sacred Heart Hospital, Hallym University College of Medicine Gyeonggi‐do Korea
4. Department of PathologyAsan Medical Center, University of Ulsan College of Medicine Seoul Korea
5. Department of Internal MedicineHanyang University Guri Hospital, Hanyang University College of Medicine Gyeonggi‐do Korea