1. Henan Key Laboratory for Esophageal Cancer Research of the First Affiliated Hospital, Zhengzhou University, Zhengzhou, Henan 450052, PR China
2. Department of Gastroenterology, the Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450014, PR China
3. Department of Pathology, Women & Infants Hospital of Zhengzhou, Zhengzhou, Henan 450012, PR China