Reduced paw swelling, but no effect on disease incidence, after treatment with 2 mg of Rac1 carboxy-terminal peptide. Mice were treated with 2 mg, 1 mg, or 0.5 mg of Ctrl (white square) or Rac1 (black square) peptide at the indicated time points. Paw swelling and inflammation of the four limbs were determined for each mouse. (a) Delta hind paw ankle joint swelling was calculated by subtracting the paw diameter on the day of initiation of treatment from the measured diameter. Values are presented as mean ± standard error of the mean (SEM) (n = 8). (b) Area under the curve (AUC) was calculated for the delta paw swelling in each mouse. Values are presented as mean AUC ± SEM. *P < 0.05. (c) Cumulative incidence of arthritis in mice for each dosage of Ctrl and Rac1 peptide was calculated. Ctrl, control.