The co-activation of NF-κB and JAK2/STAT3 induce a massive and sustained production of proinflammatory cytokines, such as IL-6 and IFN-γ, which are critical for the development of inflammatory diseases including rheumatoid arthritis (RA) and multiple sclerosis (MS) [22, 47]. Here, STAT3 is linked to rheumatoid arthritis.