The ROC curve showed that the sensitivity/specificity of CEA, ProGRP, NSE and CYFRA21-1 for the diagnosis of lung cancer were 86.84%/50.00%, 47.37%/36.11%, 84.21%/55.56%, and 86.11%/69.44%, respectively (Figure 3A). The gene discussed is ENO2; the disease is lung carcinoma.