The first correlated subset of proteins include CRP, SAA, AGP, GRO, HGF and OPN (average correlation coefficients are 0.17, 0.56 and 0.55 for normal controls, SCLC and NSCLC, respectively), while the second group of correlated proteins includes HGF, OPN, CYFR21.1, sE-selectin, MIF and NSE (average correlation coefficients are 0.14, 0.49 and 0.34 for normal controls, SCLC and NSCLC, respectively). Here, ENO2 is linked to small cell lung carcinoma.