1 Department of Pathology, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China.
2 Department of General Surgery, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China.
3 Department of Gastroenterology, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China. hwf0625@xmu.edu.cn.