Effect of anti-GM-CSF treatment post-onset on individual limb involvement. Data are from the experiment in Fig. 2 where mice were treated intraperitoneally with 300 ?g anti-GM-CSF (n = 20 mice) or isotype control (n = 19 mice) daily from the day of disease onset (day 0) until day 9 (total, 10 times). (a) The progression of arthritis in limbs already affected prior to the commencement of treatment is presented: improvement, decrease in clinical score of individual limbs following treatment; no change, clinical score of individual limbs remained the same following treatment; mild progression, clinical score of individual limbs progressed from 1 initially to 2 at the end of treatment; progression, clinical score of individual limbs progressed from 1 or 2 initially to 3 at the end of treatment (n = 33 limbs [from 20 mice], anti-GM-CSF-treated group; and n = 31 limbs [from 19 mice], isotype control-treated group) (P = 0.01; multiway chi-squared). (b) The number of limbs, initially unaffected (clinical score 0, day 0), that developed a particular score at the end of the experiment is presented (n = 47 limbs [from 20 mice], anti-GM-CSF-treated group; and n = 45 limbs [from 19 mice], control-treated group) (P = 0.0007; multiway chi-squared). There were no limbs recruited in anti-GM-CSF-treated mice that developed a clinical score > 1. GM-CSF, Granulocyte macrophage-colony stimulating factor.