Interestingly, the results of an in vitro experimental study revealed that monosodium urate crystals can activate human fibroblast-like synoviocytes (FLSs) from RA patients with a remarkable increase in the release of the inflammatory cytokine IL-6, which provided insight into the role of UA in provoking inflammation in RA [37]. This evidence concerns the gene IL6 and rheumatoid arthritis.