No statistically significant correlations were observed with sex (χ2 =0156 P = 0.693), pleural effusion (χ2 = 3.5 P = 0.063), histological grade (χ2 =2.499 P = 0.287) and TTF-1 expression (χ2 =0.276 P = 0.599). This evidence concerns the gene TTF1 and Pleural effusion.