In a 24-week open-label Phase I/II clinical trial (Clinicaltrials.gov Identifier: NCT00779194) in patients with active SLE, sirolimus treatment increased the proportion of circulating Foxp3+ Tregs, suppressed IL-17 and IL-4 secretion, and facilitated glucocorticoid tapering (mean prednisolone dose reduced from 23.7 mg to 7.2 mg daily) (236). Here, FOXP3 is linked to systemic lupus erythematosus.