TNF and rheumatoid arthritis: Five TNF inhibitors have been approved by the U.S. Food and Drug Administration for RA treatment: Remicade (Infliximab, 1998), Enbrel (Etanercept, 2001) [4–9], Humira (Adalimumab, 2003) [10–14], Simponi (Golimumab, 2011) [15–18], and Cimzia (Certolizumab Pegol, 2010) [19,20].