Lung cancer has been considered one of the most serious diseases threatening human life and health due to high mortality rate and a low overall 5 year survival rate.1,2 It is reported that the accurate determinations of disease-related biomarkers contribute to early diagnosis and increase survival.3,4 Neuron specific enolase (NSE) and progastrin-releasing peptide (31-98) (ProGRP31-98) have been reported to be good and reliable diagnostic biomarkers for small cell lung cancer (SCLC).5 NSE is a glycolytic neurospecific isoenzyme of enolase, found in nerve tissues and neuroendocrine tissues. The gene discussed is ENO2; the disease is small cell lung carcinoma.