Clinical Research Directory

Inclusion Criteria: * Male or female aged 18 years or older who undergo upper endoscopy. Exclusion Criteria: * 1)No contact information or invalid contact information. * 2\) The surveillance interval cannot be determined according to the surveillance guidelines, including no upper gastrointestinal pathology, therapeutic endoscopy or with history of previous gastrectomy, esophagectomy, or ESD, no dysplasia degrees, no biopsy sites, non-epithelial lesions, duodenal lesions, ulcer and so on. * 3\) Needless for surveillance or others. * 4\) High-grade intraepithelial neoplasia or cancer of the esophagus or stomach. * 5\) Low-grade intraepithelial neoplasia of the esophagus and Barrett's esophagus. * 6\) High-risk diseases or other special conditions for which the patient is deemed unsuitable for clinical trials by the investigator.