MX1 and juvenile dermatomyositis: Abbreviations: DM = dermatomyositis; IMNM = immune-mediated necrotizing myopathy; IIM = idiopathic inflammatory myopathy; MxA = myxovirus-resistance protein A; WB-MRI = whole-body MRI; JDM = juvenile dermatomyositis; JIIM = juvenile idiopathic inflammatory myopathy; ILD = interstitial lung disease; RP-ILD = rapidly progressive ILD; NSIP = nonspecific interstitial pneumonia.