In medical checkups and tumor reviews, physicians often prescribe some tumor markers for regular testing, whether their elevation is the occurrence of tumors, and what tumors are related to the testing of each item, we briefly introduce them one by one: the role of tumor indicators: the role of tumor indicators is to help early detection of tumors; secondly, it is important for post-operative efficacy and prognosis of tumors. For example, if a patient comes to the clinic and finds that AFP is elevated, higher than 500ug/l, the doctor will conduct CT examination on him and find tumor, which is the role of helping to diagnose, after surgery, the patient’s AFP decreases and is lower than the reference value, which means that the surgery is more complete, and then the patient will recheck AFP index every 3 months, if the AFP is found to rise again in the 6th month, then there may be recurrence and metastasis again, but tumor index cannot be the main basis of diagnosis, it only has the role of reminding and warning. However, the tumor index cannot be used as the main basis for diagnosis, but only serves as a reminder. Alpha-fetoprotein (AFP): AFP is a serum glycoprotein synthesized by the liver and yolk sac in the early stage of fetal development, therefore, physiological elevation of AFP can occur during pregnancy. If AFP is abnormally elevated above 400ug/l during this period, further prenatal testing is needed to rule out the possibility of neural tube defect malformation. In tumor testing, AFP is mainly targeted at primary liver cancer, about 90% of primary liver cancer patients can have elevated AFP, while in secondary liver cancer elevated AFP is less common. China has conducted large-scale AFP screening to affirm its role in early diagnosis of liver cancer, increasing the probability of clinical small liver cancer being detected and saving patients’ lives. In primary liver cancer, patients’ AFP is often higher than 300ug/l. The elevation of AFP is not necessarily primary liver cancer, but can also appear in patients with viral hepatitis and cirrhosis, but generally less than 300ug/l. Carcinoembryonic antigen (CEA): CEA is a broad-spectrum tumor marker, which cannot be used as a marker of a specific tumor, but is important in the efficacy and prognosis of malignant tumors. CEA is a broad-spectrum tumor marker. Elevated CEA is most commonly seen in colon cancer, but it can also be seen in breast, stomach, lung and pancreatic cancers. Other benign diseases such as intestinal polyps, colitis, cirrhosis, hepatitis and lung diseases can also show elevated CEA, but the rise is smaller. Glycochain antigen CA19-9 (CA19-9): CA19-9 is commonly found in gastrointestinal tumors and is a tumor indicator associated with pancreatic cancer, gallbladder cancer, colon cancer and gastric cancer. It can be used as an auxiliary diagnostic indicator for pancreatic cancer and gallbladder cancer. Elevated CA19-9 can also be found in benign diseases such as acute pancreatitis, cholecystitis, cholestatic cholangitis, cirrhosis, and hepatitis. In benign diseases with elevated CA19-9 patients often have jaundice, and with the relief of jaundice, total bilirubin decreases CA19-9 is restored. Cancer antigen 15-3 (CA15-3): CA15-3 is commonly found in breast cancer. In early stage breast cancer, CA15-3 sensitivity is low and in advanced breast cancer CA15-3 positivity rate can reach 80%. Elevated CA15-3 can also be seen in other tumors such as lung cancer, kidney cancer, colon cancer, pancreatic cancer, and ovarian cancer. Prostate-specific antigen assay (PSA): It is a protein enzyme secreted by the prostate epithelial cells. When prostate cancer occurs, the normal glandular structure is destroyed and PSA is elevated in the serum. The PSA is not necessarily elevated because of prostate cancer, but also because of prostate enlargement and prostatitis. CA125: CA125 is the preferred tumor indicator for ovarian cancer diagnosis and detection. It can also be positive in breast cancer, pancreatic cancer and gastric cancer, and can be elevated in non-tumor diseases such as endometriosis, pelvic inflammatory disease and ovarian cysts, which need to be distinguished as benign or malignant.