Figure 1
![Figure 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Far1503/MediaObjects/13075_2004_Article_1384_Fig1_HTML.jpg)
Box-whisker plots showing concentrations in synovial fluid for rheumatoid arthritis and healthy controls. (a) IL-6; (b) bombesin/gastrin-releasing peptide; (c) substance P. Boxes show the 25th and 75th percentiles; horizontal lines in boxes show the medians; whiskers show the 10th and 90th percentiles. *P < 0.05.