ENO2 and neuroendocrine neoplasm: NSE is a highly specific marker for neurons and peripheral neuroendocrine cells, so that increase in NSE has been used as a reliable biomarker in diagnosis, prognosis and follow-up of various diseases, such as cancer (lung cancer, neuroendocrine tumors), Guillain-Barré syndrome and Creutzfeldt-Jakob disease, etc. (28, 29).