This viewpoint was also supported in a study conducted by Chowdhury et al.18It should be emphasized that large quantities of cytokines such as IL‐1β, IL‐6, TNF‐α, transforming growth factor‐β and IL‐8 are detected in the synovial fluid and peripheral circulation of patients with RA.24, 25. This evidence concerns the gene IL6 and rheumatoid arthritis.