NSE is an important tumor marker in the serum of patients with lung cancer.20, 21 Elevated serum NSE level is also associated with neuroblastoma, neuroendocrine neoplasms, renal cell carcinoma, and other diseases.22, 23 As a neuroendocrine tumor, we hypothesized that MTC could also secrete NSE theoretically. The gene discussed is ENO2; the disease is medullary thyroid gland carcinoma.