MUC1 and interstitial lung disease: Regarding ILD indicators, the median serum KL-6 levels, %FVC, total GGO score, and total fibrosis score were 428 U/mL (range, 274–643), 95.1% (range, 81–106.7), 5.2 (range, 3–7.8), and 3.3 (range, 2–5.3), respectively.