CEACAM5 and Pleural effusion: In order to make the prediction model more suitable for doctors using in clinical work, we converted the nomogram to the scoring system: loss of weight (3 points), no fever (4 points), mediastinal lymph node enlargement (2 points), pleural effusion (6 points), effusion ADA ≦18U/L (5 points), effusion LDH >1033U/L (7 points), and effusion CEA >4.9g/mL (10 points) (Table 3).