The logistic regression model with IPF as dependent variable and KL-6 and SAA as independent variables showed AUC 0.79 (95%CI 0.67–0.91; NPP (%)66.6, PPP (%) 75.9; p < 0.0001) (Fig. 3b). This evidence concerns the gene MUC1 and idiopathic pulmonary fibrosis.