Several biological agents have been approved to treat RA, including infliximab (an anti-TNF-α mouse-human chimeric monoclonal antibody) [1], adalimumab (a fully human monoclonal antibody against TNF-α) [2], etanercept (a soluble TNF receptor-immunoglobulin chimeric protein) [3], tocilizumab (a humanized anti-interleukin-6 receptor monoclonal antibody) [4], and abatacept (a fusion protein of the extracellular domain of cytotoxic T-lymphocyte-associated antigen 4 and human immunoglobulin) [5]. This evidence concerns the gene TNF and rheumatoid arthritis.