1. Digestive Disease Center and Research Institutes, Department of Internal Medicine, SoonChunHyang University School of Medicine, Bucheon, Korea
2. Digestive Disease Center and Research Institutes, Department of Internal Medicine, SoonChunHyang University School of Medicine, Cheonan, Korea
3. Center for Liver Cancer, Hospital, National Cancer Center, Goyang, Korea
4. Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea