CEACAM5 and Pleural effusion: However, 9 months later, the patient again experienced chest pain and coughing up blood with dyspnea, serum carcinoembryonic antigen (CEA) was 91.22 ng/ml, and neuron-specific enolase (NSE) was 16.77 ng/ml, and CT imaging indicated partial pulmonary atelectasis and solid changes in the middle and lower lobes of the right lung, moderate pleural effusion on the right side, and an increase in bilateral lung lesions and regional lymph nodes (Figure 1C).