Equal RA synovial fibroblast numbers (n = 4 donors) were detected in the nonstimulated and MIF-stimulated (50 nM) wells after 24-hours incubation (mean fluorescence intensity, 495 ± 25 versus 478 ± 19, respectively; P > 0.05 (data not shown)). Here, MIF is linked to rheumatoid arthritis.