MUC1 and interstitial lung disease: This analysis demonstrated that the clinical and serum biomarker signature consisting of age, KL-6, and TNFα effectively differentiated pSS–ILD from pSS–no ILD with high sensitivity and specificity, yielding an AUC of 0.883 (95% CI = 0.7987–0.9677, p value < 0.0001) (Fig. 3).