1 .The test result is close to the upper limit of the reference value, is there a problem? A: No problem. As long as the test result is within the reference value, it is normal. 2.Does it necessarily mean that a tumor is present if the test result of a tumor marker exceeds the normal range? A: Not necessarily. A tumor can never be diagnosed based on one tumor marker being higher than the normal range. However, if the tumor markers are higher than normal, we should pay attention to them and conduct further examination. Especially when a certain marker increases progressively. 3. What is the clinical role of tumor markers? The main role of tumor markers is to screen for tumors and to follow up patients with diagnosed tumors after treatment. 4.How is the normal range of tumor markers determined? A: The reference range of tumor markers is determined by the mean ± 1.96 times the standard deviation (x ± 1.96s) of the measured values of a certain index in a normal population. In fact, the normal range of tumor markers does not include the measured values of all normal people, but only the measured values of 95% of normal people, that is, 5% of normal people may have the measured value of a certain index outside the normal range.