IL6 and autoimmune disease: Rheumatoid arthritis (RA) is a common autoimmune disease, characterized by systemic inflammation and immunological high disability.[1] Interleukin 6 (IL-6) is a pro-inflammatory cytokine and secreted by T cells and macrophages to stimulate immune response, and plays an important role in the development of RA.[2] IL-6 aggravates the immune imbalance between regulatory T cells (Treg) and Th17 cells, and promotes the production of autoantibodies.