High NSE is not necessarily lung cancer. Elevated NSE can be seen in lung cancer, neuroblastoma and other diseases, as well as in hemolysis of normal specimens. NSE, neuron-specific enolase, is mainly associated with tumors of neuroendocrine origin. The level of NSE in small cell lung cancer is significantly higher than that of squamous and adenocarcinoma, so it can be used for diagnosis, differential diagnosis, and efficacy monitoring of small cell lung cancer. It may also be used to assist in the diagnosis of neuroblastoma and to detect efficacy and recurrence. However, NSE also exists in normal red blood cells and can be elevated when hemolysis is caused by improper specimen preservation or handling. Therefore, high NSE does not necessarily mean that one has lung cancer. It is recommended that the patient should consult the doctor in time, analyze the cause of the disease according to the results of other tumor indicators and imaging examinations, and follow the doctor’s instructions for further examination and treatment.