FOXP3 and systemic lupus erythematosus: Although the therapeutic effects of TGF-β1 on SLE produced by CD4+CD25+Foxp3+ Tregs, which also produce IL-10 (2), have not been verified, IL-10-producing LAG3+ Tregs exist in the steady state and TGF-β3 produced by LAG3+ Tregs showed therapeutic effects on lupus pathologies (3, 6).