In SLE, increased levels of circulating CD4+ ICOS+ Foxp3+ T cells contribute to IL-10 production and correlate with disease severity, the SLE activity index, and serum anti-dsDNA (although the authors suggested that these ICOS+ Tregs may be the precursors of inflammatory cells) [95]. This evidence concerns the gene FOXP3 and systemic lupus erythematosus.