When we applied the cut-off value and analyzed the outliers, such as the patients who had higher KL-6 levels than the cut-off value with CT grades 1–2 (n = 14), 12 of the 14 patients had underlying SSc (n = 3) or IM (n = 9) (Fig. 3). The gene discussed is MUC1; the disease is systemic sclerosis.