CD4 and systemic lupus erythematosus: In line with this observation, we found that the proportions of total T cells (CD3+), CD4+ T cells (CD3+CD4+), NK cells (CD3−CD56+), NKT cells (CD3+CD56+) and Treg cells (CD4+CD25+ Foxp3+) were dramatically decreased (Supplementary Figure 1), while frequencies of Th1 cells (CD3+CD4+ IFN-γ+), Th2 cells (CD3+CD4+ IL-4+) and Th17 cells (CD3+CD4+ IL-17+) were increased in PBMCs of patients with SLE, as compared with HCs (Supplementary Figure 1B and C).