TNF and rheumatoid arthritis: Certain pro-inflammatory cytokines e.g., TNF-α, interleukin-1 (IL-1), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and interferon gamma (IFNγ) are considered as the primary mediators which have a vital role in the pathophysiology of RA.