CEACAM5 and pulmonary emphysema: (1) Y = 0.275 × age + 0.704 × smoking + 0.29 × diameter + 0.38 × emphysema + 0.891 × vascular sign + 0.481 × burr + 2.775 × (CYFRA21-1) + 0.061 × CEA + 0.304 × (miRNA-21-5p) − 2.778 × (miRNA-574-5p); (Y > 0 ruled malignant; Y < 0 ruled benign).