Furthermore, previous studies have shown that in addition to IL-1β, IL-6, and IL-8, other cytokines, such as TNF-α and IFN-γ, are also elevated in RA articular fluid [22–25], but in this study, there was no significant difference compared to the concentrations observed in OA synovial fluid. The gene discussed is CXCL8; the disease is rheumatoid arthritis.