C3 and systemic lupus erythematosus: Similar observations of increased numbers of CD4+CD25-Foxp3+ T cells in patients with active as compared to inactive SLE or HC were further made by Zhang et al. Moreover they also reported direct correlation between proportions of CD4+CD25-Foxp3+ T cells and concentrations of antibodies against dsDNA, whereas no correlation was observed for the C3 levels and the SLEDAI score [19].