The significance of tumor marker(TM) testing is summarized as follows: i. Tumor screening Tumor screening is to find suspicious people from asymptomatic people. Tumor marker test is an effective method for initial screening of tumors. It is often used for screening of high-risk groups. AFP: Screening for primary liver cancer. PSA: Screening for prostate cancer in men over 50 years old. High-risk HPV : Screening for cervical cancer. CA125+Ultrasound : Screening for ovarian cancer in women over 50 years of age. Abnormally elevated tumor markers without obvious symptoms and signs need to be reviewed and followed up. If it continues to increase, the diagnosis should be confirmed in time. Diagnosis Auxiliary diagnosis: The specificity of tumor markers is not strong enough, and the diagnosis of tumor cannot be confirmed solely based on tumor markers, but it can provide clues for further diagnosis. Differential diagnosis: Ben-Hur protein, AFP, HCG, PSA, etc. have characteristic cancer spectrum. Cannot be diagnosed locally: tumor markers lack tissue and organ specificity. Dynamic observation: progressive elevation of tumor markers has clear diagnostic significance; the elevation of markers in benign diseases is transient; the elevation of markers in malignant tumors is persistent. Monitoring the disease and efficacy Monitoring the efficacy and recurrence of metastasis is the most important clinical application of tumor markers. After surgery, chemotherapy or radiotherapy, there is a good correlation between the increase and decrease of specific tumor markers and the efficacy of treatment, and the dynamic observation can reflect whether the tumor has recurrence or metastasis.