TNF and arthritic joint disease: Several studies have reported that C-reactive protein (CRP), leukotriene B4 (LTB4), prostaglandin E2 (PGE2), interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-α) play crucial roles in inflammatory processes and the pathophysiology of arthritis (Choy and Panayi 2001; McInnes and Schett 2007; Abramson 2008; Goldring and Otero 2011; Ahn et al. 2021).