Lung cancer blood markers include: carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC), cytokeratin fragment 21-1 (CF21-1), neurospecific enolase (NSE), gastrin-releasing peptide precursor (ProGRP), and CA125. Carcinoembryonic antigen (CEA): mainly found in the epithelium of the digestive tract, pancreas and liver, the sensitivity in non-small cell lung cancer is 40-60%, among which elevated in adenocarcinoma is more common, which is of significance in the evaluation of the prognosis and efficacy of lung cancer. Squamous cell carcinoma antigen (SCC): it is a tumor marker for distinguishing squamous lung cancer from adenocarcinoma of the lung, and is often used in the evaluation of the efficacy and prognosis of squamous lung cancer. Cytokeratin fragment 21-1 (CF21-1): abundant in non-small cell lung cancer tissues, which has an important role in suggesting lung squamous carcinoma. Neuro-specific enolase (NSE): produced by malignant tumors of central and peripheral neurons and neural ectoderm, it has high diagnostic specificity for small cell lung cancer and is a marker for small cell lung cancer. Gastrin-releasing peptide precursor (ProGRP): many tumor tissues of small cell lung cancer can produce and secrete gastrin-releasing peptide precursor, which is an autonomous growth factor in small cell lung cancer. CA125: It is of great significance in the efficacy evaluation and prognosis of lung adenocarcinoma. Warm reminder: Blood tumor markers are used for the auxiliary diagnosis of lung cancer and the evaluation of efficacy and prognosis, but it is still necessary to consult professional hospitals, and combine with imaging and clinical symptoms for comprehensive analysis of diagnosis and treatment.