We utilized pretreatment samples from the ADACTA trial, a randomized, double blind, controlled phase-4 head to head study of tocilizumab (a humanized monoclonal antibody that binds to membrane-bound and soluble forms of the human IL-6 receptor) monotherapy, compared with adalimumab (a fully human monoclonal antibody against TNFα) monotherapy, in methotrexate-intolerant patients with active RA [30]. Here, TNF is linked to rheumatoid arthritis.