CD4 and systemic lupus erythematosus: In addition to inhibiting the secretion of proinflammatory cytokines, MSCs can also induce naïve CD4+T cells to differentiate into Tregs (Luz-Crawford et al., 2013; Wang et al., 2017a), indicating that allogeneic MSC transplantation may be able to restore the balance between Treg and Th in SLE patients.