These include PEGylated IL-2 (NKTR-358 “LY3471851”) (303), which induced clinical response and dose-dependent changes in Treg functional markers in a phase I trial in mild-to-moderate SLE, various IL-2:IL-2 Ab complexes described as CD25-directed IL-2cx (283, 284) and CD25-IL2 fusion proteins (287, 288). Here, IL2RA is linked to systemic lupus erythematosus.