In contrast to AREG, serum HB-EGF levels were not substantially different between HC and IIM patients with and without ILD (HCs: median, 74.9 pg/mL (IQR: 56.8–98.0); IIM patients without ILD: median, 90.6 pg/mL (IQR: 71.7–138.1); IIM patients with ILD: median, 75.9 pg/mL (IQR: 50.8–106.5)) (Figure 2A). Here, AREG is linked to interstitial lung disease.