More recently, Ke et al. have proven that sTNF-R1 released by skin-derived mesenchymal stem cells is critical for inhibiting the differentiation of Th17 cells, which are the major contributor of experimental murine models of autoimmune disease leading to IL-17A, IL-17F, IL-21, and IL-22 production (59). This evidence concerns the gene IL21 and autoimmune disease.