BM-derived and SM-derived MSC were shown to express CD44, CD73, CD90 and CD105 in the same range and to respond to IFN stimulation. We showed that IFN-β, IFN-α2 and IFN-γ are able to stimulate the expression of MHC class I and class II molecules on the MSC surface from both origins. Using quantitative analysis, we demonstrated similar differentiation capacities (osteogenesis and chondrogenesis induction) for BM-derived or SM-derived MSC. Moreover, our data are the first to show the same immunosuppressive features in mixed lymphocyte reaction (>90% of T-cell proliferation inhibition) and similar expression of indoleamine 2,3-dioxygenase in BM-derived and SM-derived MSC. Nevertheless, the macroarray analysis shows a statistically significant discrimination between SM-derived and BM-derived MSC, in particular inflammatory cytokine as IL6 and IL8 were upregulated in synoviocytes compared with BM-MSC. Validation in terms of expression of specific proteins is being undertaken.