CD74 and juvenile dermatomyositis: IFITM2+ and CYP4F3+ monocytes in peripheral blood, and CD74+ SMCs and CCL19+ fibroblasts in muscle were identified as inflammatory-related cell subtypes in JDM patients, and they could acquire inflammatory states via the coordinated activity of inflammatory pathways, especcially driven by response to IFN-γ and type I IFN-mediated signaling pathway.