IL6 and rheumatoid arthritis: Besides, baricitinib has also been approved by the European Union in March 2017 and Japan in July 2017 for the treatment of moderate to severe rheumatoid arthritis for inhibiting the intracellular signaling of many inflammatory cytokines such as IL-6 and IL-23 [3–5] and for the patients with rheumatoid arthritis and poor response to the current standard treatment [2], respectively.