The results were shown in Table 3 and demonstrated that SUVmax were significantly higher in lung cancers than in benign lesions (P<0.001); NSE was also found significantly higher in SCLC than in NSCLC and benign lesions (P<0.001); in contrast, CEA, CYFRA21-1 and SCC-Ag shown no significant difference among benign lesions, NSCLC and SCLC (P = 0.503). This evidence concerns the gene ENO2 and small cell lung carcinoma.