IL10 and arthritic joint disease: Minglu Yan et al. reported that human synovial membrane-derived MSCs can inhibit the maturation and differentiation of B cells; induce CD21highCD23high transitional 2 (T2) cells, CD23lowCD21high marginal zone (MZ) cells, and CD5+CD1d+IL-10 cells in the spleen; and increase the numbers of immature transitional B cells, such as IL-10+ cells, thus reducing the severity of arthritis in mice (71).