CSF2 and rheumatoid arthritis: GM-CSF has been identified as an importantmediator in the progression of both pain and disease in an experimentalOA model, in addition to its known role in rheumatoid arthritis. G-CSF whose levels rise markedly under stressplays a role in regulating the inflammatory response in models ofinflammatory arthritis. However, thedirect role of protease upregulation in MSC-derived chondrocytes andcolony-stimulating factors (CSFs) still needs to be established.