FOXP3 and systemic lupus erythematosus: Consistent with previous findings [7], [8], we confirmed that the frequency of FOXP3+ cells among CD127lowCD25low T cells (gating strategy Fig. 1B) was markedly increased in SLE patients (geometric mean (GeoM) = 13.5%) compared to age- and sex-matched healthy controls (5.5%, P = 2.1 × 10−5, N = 24, Fig. 1C), which likely reflects the systemic immune activation in SLE patients.