1. Department of Respiratory Medicine; Sir Run Run Shaw Hospital; Zhejiang University School of Medicine; Hangzhou; China
2. Department of Gastroenterology; First Affiliated Hospital of Zhengzhou University; Zhengzhou; China
3. Department of Hepatobiliary and Pancreatic Surgery; First Affiliated Hospital of Zhengzhou University; Zhengzhou; China
4. Department of Gastroenterology; Ruijin Hospital; Shanghai Jiaotong University School of Medicine; Shanghai; China
5. Department of Pathology; First Affiliated Hospital of Zhengzhou University; Zhengzhou; China