CD4 and systemic lupus erythematosus: Similar results were also obtained in the lymph nodes, where S100A9 deletion significantly reversed the activation of macrophages (Fig. 6H, Supplementary Fig. 5C) and DCs (Fig. 6I, Supplementary Fig. 5D), reduced the activation of B cells (Supplementary Fig. 7A, B) and CD4+ T cells (Supplementary Fig. 7C, D) and decreased the percentage of germinal center B cells (Supplementary Fig. 7E, F) and plasmacytes (Supplementary Fig. 7G, H) in the mLNs of IMQ-induced lupus mice.