CD4 and systemic lupus erythematosus: Compared to healthy controls (HC) and according to our observations in NZB/WF1 mice (Supplementary Figure 2A; Supplementary Table 2), SLE patients displayed significantly increased immune activation, determined by expression of HLA-DR on CD3+CD4+, CD3+CD8+ and whole CD3+ T cells (Figures 5A, B).