NSE, short for neuron-specific enolase, is an acidic protease specific to neurons and neuroendocrine cells, and is the most sensitive and specific tumor marker for small cell lung cancer. The second is that increased secretion can also be seen in neuroblastoma and endocrine tumors. increased NSE can be seen in small cell lung cancer, neuroblastoma, including neuroendocrine cell tumors, melanoma, islet cell tumors, etc. Once elevated NSE is found, it indicates the possibility of having the above tumors. In case of high NSE, while being alert to the above tumors, we should also pay attention to review and review at certain intervals, not necessarily as a tumor, but only as a hint to be alert to the above tumors.