IL6 and rheumatoid arthritis: Average control values for cytokines (dotted line at 100 % in Fig. 1) were 110 ± 44 ng/ml (OA) and 148 ± 49 ng/ml (RA) for IL-6, 103 ± 49 ng/ml (OA) and 171 ± 56 ng/ml (RA) for IL-8, and 66 ± 68 pg/ml (OA) and 163 ± 166 pg/ml (RA) for TNF.