In clinical studies with RA patients, MSC therapy resulted in an increased T regulatory (Treg)/Th17 cell ratio (31, 32) and improved immune balance as indicated by decreased IL-1β, IL-6, IL-8 and TNFα, as well as increased production of IL-10 and transforming growth factor (TGF)β (29, 33). This evidence concerns the gene IL1B and rheumatoid arthritis.