The laboratory data from the pleural effusion were as follows: number of cells: 468/mL (78.5% mononuclear cells and 80.9% atypical cells); lactate dehydrogenase: 2022 U/L; adenosine deaminase: 52.4 U/L; and cytokeratin 19 fragment: 4.29 ng/mL. This evidence concerns the gene KRT19 and Pleural effusion.