We also found that RA STs contained a greater percentage of fut1-positive synovial macrophages than did OA or NL STs; mean number of synovial macrophages ± SEM; RA ST (n = 26) 17 ± 2%; OA ST (n = 22) 6 ± 2% and NL ST (n = 18) 2 ± 1%, P <0.05 between RA and OA ST; RA and NL ST (Figure 2D). Here, FUT1 is linked to rheumatoid arthritis.