1. Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
2. Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea
3. Department of Internal Medicine, Inje University Busan Paik Hospital, Busan, Korea
4. Department of Internal Medicine, Jeonbuk National University Hospital, Jeonju, Korea
5. Department of Internal Medicine, Chonnam National University Hwasun Hospital, Hwasun, Korea
6. Department of Internal Medicine, Asan Medical Center, Seoul, Korea
7. Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea
8. National Cancer Center, Goyang, Korea