Neuron-specific enolase is an enzyme involved in the glycolytic pathway. A 7mm nodule on the lung with neuron-specific enolase 20.93ng/ml is not necessarily a tumor. At neuron-specific enolase higher than 16.3ng/ml, it suggests a risk of malignancy, but not necessarily a tumor. Under normal circumstances, the normal index of neuron-specific enolase is <16.3ng/ml. In the case of neuron-specific enolase >16.3ng/ml, it suggests that the risk of malignant lesions exists, but it is not necessarily cancer; it may just be a benign nodule in the lungs, but malignant tumors, such as small-cell lung carcinoma, can’t be completely excluded. However, the neuron-specific enolase index alone cannot accurately assess whether it is a tumor or a benign tumor, and the diagnosis has to be made at a later stage in conjunction with other items of tumor markers as well as pathological biopsy. If neuron-specific enolase is found to be high, it is recommended to consult a doctor in time and under the guidance of a professional physician to carry out the next step of examination, including chest X-ray, endoscopy, cytology, histology, etc., so as to make a clear diagnosis before proceeding with the treatment.