At the time of diagnosis, the prognostic role of KL‐6 already reported in literature is further confirmed by our results, showing indirect correlations between serum measurements of KL‐6 and DLco% (r = −0.3011) and FVC% (r = −0.3744) highlighting patients with more advanced ILD, mainly those with IPF (a progressive fibrotic ILD). The gene discussed is MUC1; the disease is interstitial lung disease.