IFIH1 and dermatomyositis: Anti-melanoma differentiation-associated gene 5-positive dermatomyositis (MDA5+DM) is a rare but distinct subtype of dermatomyositis (DM), which is typically characterized by anti-MDA5 autoantibody, DM rash, multiple arthralgia, and interstitial lung disease (ILD), while the clinical signs of myositis are usually absent.[1,2] Due to the high incidence of rapidly progressive interstitial lung disease (RP-ILD), MDA5+DM is usually associated with poor prognosis and high mortality, both in East Asia and Western countries.[3,4,5,6,7]