TNF and rheumatoid arthritis: Importantly, the success of biological therapies that directly target key cytokines such as TNF inhibitors (adalimumab, infliximab, etanercept, golimumab and certolizumab); tocilizumab (an IL-6R antagonist) and anakinra (an IL-1R antagonist) in RA further reinforce the relevance of these small proteins in disease development (42–46).