Eleven candidate proteins (CEA, CYFRA21.1, MIF, AGP, HGF, E-selectin, GRO, OPN, SAA, CRP, and NSE) were analyzed in serum samples from 218 NSCLC patients, 34 SCLC patients and 171 normal controls using Luminex multiplex assays. The gene discussed is ENO2; the disease is non-small cell lung carcinoma.