△CtCa < △CtN indicated that the expression of SMO and GLI1 in mesothelioma tissues was higher than that in benign mesothelioma tissues; △CtCa > △CtN indicated that the expression in mesothelioma tissues was lower than that in benign mesothelioma tissues, and P < 0.05 was statistically significant. The gene discussed is SMO; the disease is benign mesothelioma.