IFIH1 and interstitial lung disease: As in cluster 2, similar to those of previous myositis cohort studies in other countries,9, 10 MDA5+ RP-ILD patients with a typical dermatomyositis-specific rash and higher mortality were grouped in one cluster, suggesting that heliotrope rash, Gottron papule, ILD and anti-MDA5 antibodies are key risk factors for poor prognosis in DM.