An increase in NSE has been found in cerebral ischemia and neuronal injury due to a variety of reasons, such as neonatal asphyxia, pediatric febrile seizures, brain infectious diseases, chronic obstructive pulmonary disease, cerebral infarction, cerebral hemorrhage, systemic lupus erythematosus, Wilson's degeneration, and depression. This evidence concerns the gene ENO2 and major depressive disorder.