IFIH1 and polymyositis: The classification of IIM encompasses several subgroups, including dermatomyositis (DM), antisynthetase syndrome, immune-mediated necrotizing myopathy, inclusion body myositis, polymyositis, and overlap myositis.[1] Among these, interstitial lung disease (ILD) associated with IIM presents a significant clinical challenge, with melanoma differentiation-associated gene 5 (MDA5)-related lung disease exhibiting particularly rapid progression.