To define the effects of low-dose recombinant human IL-2 (rhIL-2) treatment on regulatory and effector CD4+ T-cell subsets in patients with active SLE, He et al.29 gave 40 patients with active SLE2 MIU IL-2 every other day for 2 weeks followed by a 2-week hiatus, and demonstrated that low-dose IL-2 could both increase the numbers of CD25highCD127low Treg cells and enhance their function, and that the ratio of TFH+ TH17 cells/Treg cells fell significantly. Here, IL2 is linked to systemic lupus erythematosus.