In an exploratory analysis of the rapid-progressive ILD subgroups, KL-6 and B-lines showed only modest predictive value (AUC ≈ 0.65).<h4>Conclusion</h4>KL-6 ≥553 U/mL and B-lines ≥25 are effective screening thresholds, with combined use significantly improving diagnostic accuracy. Here, MUC1 is linked to interstitial lung disease.