CD4 and myositis disease: We therefore performed comparative scRNAseq analysis of WT, OT-II TCR transgenic, CD4-Cre.MyD88fl/fl, and RAG1 KO mice immunized with recombinant HRS to define the impact of targeted disruption of T cell activation/signaling on the relative distribution and transcriptomic profiles of different macrophage subsets in HRS-induced myositis.