Importantly, in untreated rheumatoid arthritis (RA) patients, expression of Arid5a in CD4+ T cells is increased, whereas treatment with the anti-IL-6 receptor antibody tocilizumab is associated with decreased Arid5a expression (306), indicating that the IL-6-ARID5a axis may be involved in RA pathogenesis. This evidence concerns the gene CD4 and rheumatoid arthritis.