Inclusion Criteria:  Age≥40 Received EGD; Subjects must have given written informed consent, and the subjects compliance are good.  Exclusion Criteria:  Subjects who could not accept EGD; Subjects who had previously undergone total or partial gastrectomy; There are other serious acute or chronic medical or mental diseases or laboratory abnormalities that may interfere with the interpretation of the research results and make the subjects unsuitable for the study in the judgment of the researchers; Subjects with a history of malignant tumor or two or more malignant tumors at the same time; Pregnant subjects; Subjects who had a history of bone marrow or organ transplantation, or had a history of blood transfusion one month before enrollment. The subjects with incomplete clinical data collection or other reasons judged by the researchers are not suitable for this study.