1. Department of Pathology, Nangang Brach, Heilongjiang Provincial Hospital, Harbin, Heilongjiang, China
2. Division III, Department of Gastroenterology, Nangang Brach, Heilongjiang Provincial Hospital, Harbin, Heilongjiang, China
3. Division III, Department of Oncology, General Hospital of Heilongjiang Province Land Reclamation Bureau, Harbin, Heilongjiang, China
4. Department of Pediatrics, Harbin Red Cross Central Hospital, Harbin, Heilongjiang, China