- Serum levels of matrix metalloproteinase 3 and macrophage colony-stimulating factor 1 correlate with disease activity in ankylosing spondylitis. Yang, C., Gu, J., Rihl, M., Baeten, D., Huang, F., Zhao, M., Zhang, H., Maksymowych, W.P., De Keyser, F., Veys, E.M., Yu, D.T. Arthritis Rheum. (2004)