CD4 and systemic lupus erythematosus: It has reported that TGF-β1 released from MSCs leads to wound contraction and vessel formation (Jiang et al., 2020); other demonstrated that MSCs-released TGF-β1 promote CD4+CD25+Foxp3+ iTreg cells generation from human SLE PBMCs by to control SLE disease (Darlan et al., 2021).