Lastly, an increase in serum IL-2 positively correlated with the reduction of disease activity of SLE patients by UC-MSCs.<h4>Conclusion</h4>Both the single injection of UC-MSCs and repeated IL-2 administration exerted comparable efficacy in alleviating SLE manifestations, but UC-MSCs provided sustained alleviation and showed better improvement in renal pathology. Here, IL2 is linked to systemic lupus erythematosus.