MUC1 and idiopathic pulmonary fibrosis: In the IPF group, ROC curve analysis showed the best areas under the curve than for the other ILDs for KL-6 (AUC = 0.80, 95%CI 0.71–0.90; p < 0.0001) and SAA (AUC = 0.69, 95%CI 0.61–0.77, p < 0.0001) (Fig. 2a).