In view of previous research having reported that the cartilage differentiation ability of BM-MSCs will be inhibited by inflammatory cytokines such as interleukin (IL)-1β, tumor necrosis factor alpha (TNFα), and IL-17, it is speculated that the difference of chondrogenesis potential of SM-MSCs derived from RA in these different research groups may be due to the different inflammatory levels of the selected donors in each experimental study. Here, TNF is linked to rheumatoid arthritis.