The cut-off baseline serum KL-6 value for predicting severe TR-ILD in category 3 was 302.4 U/mL with a sensitivity of 76.9% and a specificity of 55.7% (AUC: 0.625, 95% CI 0.521–0.722; p = 0.057) (see Supplementary Fig. S2e online). The gene discussed is MUC1; the disease is interstitial lung disease.