Figure 7 indicates that multiple cell types contribute to the signaling milieu favoring activation of macrophages and fibroblasts which are responsible for promoting key inflammatory cascades underlying HRS-induced myositis. While TNFα, IFNγ, TGFβ, IL-6, CCL2, CCL3, CCL4, CXCL9, and CXCL12 drive the activation of macrophages in WT versus RAG1 KO, OT-II, and CD4-Cre.MyD88fl/fl conditional KO mice, TNFα, IFNγ, IL-1β, IL-6, IL-8, CXCL9, and CXCL12 represent key cytokines/chemokines promoting pro-inflammatory pathways in WT fibroblasts. Here, IL1B is linked to myositis disease.