The peptide-induced regulatory T cells in lupus PBMC depended on TGFβ/ALK-5/pSmad 2/3 signaling, and TGF-β precursor LAP was expressed by those Treg cells, indicating that TGFβ production was responsible for their suppressive activity, and a positive feedback mechanism as well. This evidence concerns the gene TGFB1 and systemic lupus erythematosus.