TNF and rheumatoid arthritis: Biologic agents commonly used in Japan for the treatment of RA include antitumor necrosis factor (anti-TNF) agents such as infliximab (IFX), etanercept (ETA), adalimumab (ADA), golimumab (GLM), and certolizumab pegol (CZP); an inhibitor of T-cell costimulation (abatacept (ABT)); an inhibitor of interleukin- (IL-) 6 receptor (tocilizumab (TCZ)); and a small-molecule Janus-associated kinase (Jak) inhibitor (tofacitinib (Tofa) and baricitinib).