In plasma cavity effusion specimens, SMO positive expression rates were 22.00% (11/50) and 73.08% (95/130) in benign mesothelial tissue and malignant mesothelioma, respectively (P < 0.05, Table 6); GLI1 positive rates were 32.00% (16/50) and 66.15% (86/130), respectively, with statistically significant differences (P < 0.05, Table 6). The gene discussed is GLI1; the disease is malignant mesothelioma.