MUC1 and interstitial lung disease: A number of circulating biomarkers have been shown to be useful in assessing disease activity and/or predicting the outcomes of ILD in patients with connective tissue diseases, including PM/DM; these biomarkers include autoantibodies, pneumoproteins, such as Krebs von den Lungen-6 (KL-6) and surfactant protein D (SP-D), and inflammation-related proteins, such as C-reactive protein (CRP) and a variety of cytokines and chemokines [3].