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. This evidence concerns the gene ENO2 and small cell lung carcinoma.