MUC1 and interstitial lung disease: Previous reports showed that high serum Krebs von den Lungen-6 (KL-6) levels, serial KL-6 increases, and the presence of middle lobe traction bronchiectasis on high-resolution computed tomography (HRCT) were associated with the deterioration of myositis-associated ILD, including anti-ARS-ILD (15, 16).