Synovial nucleated cells before culture generally expressed hematopoietic markers such as HLA-DR, CD11b, CD11c, CD31 and CD45 at low or moderate levels, and MSC markers such as CD44, CD73, CD90 and CD105 at moderate levels in both RA and OA groups (Fig. 4, Additional file 1: Figure S1 and Figure S2 and Additional file 2: Table S1). Here, CD44 is linked to rheumatoid arthritis.