FUT1 and rheumatoid arthritis: HMVECs harvested from the fut1 siRNA-transfected RA synovial fibroblast co-culture system had decreased EC tube formation compared with HMVECs harvested from the control siRNA or the nontreated RA synovial fibroblast co-culture system (number of EC tubes formed per high power field ± SEM; 4 ± 2, 23 ± 1 and 27 ± 1, respectively; P < 0.05, Figure 3B and C).