SMAD7 and systemic lupus erythematosus: PBMCs from SLE patients stimulated with IL-2 promoted production of IFNγ and increased proliferation of PBMCs; however, administration of TGF-β1 in IL-2-treated PBMCs suppressed IFNγ production and proliferation of PBMCs and downregulated Smad family member 7 (Smad7) expression in PBMCs (110).