IL6R and rheumatoid arthritis: Because of this pathological role, IL-6 represented an attractive therapeutic target in RA, and tocilizumab, a humanized anti-IL-6R monoclonal antibody of the IgG1 class, was approved in Europe in 2009 as intravenous injections (and in 2013 as subcutaneous injections) for the treatment of adult patients with RA.