TNF and rheumatoid arthritis: Inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-17 (IL-17), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), etc., can promote the augment of RANKL and M-CSF after binding to the receptors on osteoclasts, so as to aggravate bone resorption in RA.