Murine synovial fibroblasts have impaired migration towards citrullinated fibronectin. Synovial fibroblasts were allowed to migrate for 6 hours towards no additive (Null), fibronectin (FN), citrullinated fibronectin (FNC), or fibronectin incubated with heat-inactivated peptidyl arginine deiminase (FNHI). Graph shows the average number of migrated cells per 10× field with standard error for five experiments. Ten 10× fields were counted for each sample. *P < 0.05, ***P < 0.005.