TNF and rheumatoid arthritis: Tocilizumab, the first humanized monoclonal antibody against IL-6R, could inhibit all IL-6R-mediated signaling by intravenous or subcutaneous injection, alone or in combination with methotrexate, for the treatment of RA in adults who have either responded inadequately to or were intolerant of previous therapy with ≥ 1 csDMARDs or TNF inhibitor (41).