IFIH1 and Skin ulcer: In first, we identified the incidence of typical rash, including the heliotrope, Gottron, V, and Shawl signs, and skin ulcer and the levels of serum alanine transaminase (ALT), aspartate transaminase (AST), and ferritin were significantly higher, whereas CK levels in MDA5+ DM patients with RP-ILD were much lower (all p values < 0.05).