FOXP3 and rheumatoid arthritis: Recently, a subset of FOXP3+ CD4+ T cells with low expression of CD25 was reported to be increased in peripheral blood of autoimmune systemic lupus erythematosus (SLE) patients [5], [6], [7], [8], [9], a finding that was later expanded to the peripheral blood of multiple sclerosis [10] and rheumatoid arthritis [11] patients.