1 Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China.
2 Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China; The School of Clinical Medicine, Fujian Medical University, Fuzhou, China. Electronic address: hwf0625@xmu.edu.cn.