Tumor four refers to the four tests commonly used for tumor markers, and each hospital and each system contains different contents, and the following combinations are more commonly used clinically: lung cancer four, CEA, NSE, CA19-9, CYFRA21-1; breast cancer four, CEA, CA15-3, CA19-9, CA125; gastrointestinal tract tumor four, CEA, AFP, CA19-9, CA242; gynecological tumor quadruple, CEA, AFP, CA125, CA15-3; stomach cancer quadruple, CEA, CA72-4, CA19-9, CA242. in short, tumor quadruple is an important element in the exclusion of cancer screening, which can be based on the patient’s specific situation to decide the specific options.