IL2 and systemic lupus erythematosus: Considering the fact that the IL-2 mRNA levels in CD3+ T cells have no significant difference between SLE patients and HCs, and sIL-2Rα in peripheral blood of SLE patients is produced in large quantities and can combine with IL-2 to form immune complex, we speculate that whether the decrease of serum IL-2 level in SLE patients is due to the false decrease of IL-2 detection caused by the formation of sIL-2Rα/IL-2 complex.