ENO2 and neoplasm: To the best of our knowledge, this is the first study to evaluate the clinical utility of seven tumor markers CEA, CA19-9, CA125, AFP, NSE, CA15-3, and CYFRA21-1 for prognostic specification as well as for measuring the response of chemotherapy (2-drugs vs. 3-drugs) in terminal stage (IV) NSCLC patients who underwent palliative chemotherapy.