Since then, other studies, mainly focusing on SSc, have shown the reliable diagnostic and prognostic value of KL-6 in SARD-ILD: KL-6 seems able to distinguish patients with and without lung involvement at an early stage and shows moderate to high correlations with lung function parameters and quantitative HRCT scores of lung interstitial involvement [41]. This evidence concerns the gene MUC1 and interstitial lung disease.