MUC1 and interstitial lung disease: Upon further analysis, we showed that the area under the curve (AUC) of the receiver operating characteristic (ROC) curve from KL-6 is 0.76, higher than 0.69 from Raynaud’s phenomenon (Table 6 and Fig. 5), which suggested the serum KL-6 level indeed has a decent, if not better, predicting value as a risk factor for ILD occurrence.