The cut-offs and AUCs of effective tumor markers for diagnosing cytology-negative MPE were as follows: 2.4 ng/ml [AUC, 0.769 (0.740–0.796)] for PE CEA and 3.0 ng/ml (AUC, 0.789 (0.761–0.815)) for serum CYFRA21-1 (Table 5). This evidence concerns the gene CEACAM5 and neoplasm.