Recent pre-clinical study has discovered that hUCB-MSCs can promote the transition of macrophages tilting the equilibrium toward the formation of M2-type cells by the tumor necrosis factor (TNF)-α-mediated activation of cyclooxygenase-2 and TNF-stimulated gene/protein 6 in hUCB-MSCs, a process that favors cartilage production and thus repair of inflammatory damages in RA [53]. This evidence concerns the gene TNF and rheumatoid arthritis.