MUC1 and idiopathic pulmonary fibrosis: According to the multivariate logistic regression analysis, age >65 years (OR 2.71, 95% CI 1.26-5.89; p = 0.011), LDH >245 U/L (OR 3.07, 95% CI 1.39-6.78; p = 0.006), CA-153 > 35 U/mL (OR 3.16, 95% CI 1.25-7.97; p = 0.015), FVC <60% predicted (OR 4.82, 95% CI 1.60-14.51; p = 0.005), DLCO <50% predicted (OR 3.21, 95% CI 1.43-7.21; p = 0.005), and the UIP-like pattern on chest HRCT (OR 3.65, 95% CI 1.33-10.07; p = 0.012) were potentially associated with the progression of fibrotic interstitial lung diseases (f-ILDs) to PPF.