IL6 and rheumatoid arthritis: Indeed, there are over 50 cytokines that signal through JAK‐mediated type I and II receptors,6 many implicated in inflammatory disease pathophysiology.1, 4 Notably, IL‐6 induces acute‐phase proteins such as C‐reactive protein (CRP) and may be involved in the autoimmune process through B‐cell modulation and T‐helper‐17‐cell differentiation.7 Common γc cytokines play a key role in adaptive immune functions, for example, in T‐cell and natural killer (NK)‐cell differentiation.5 JAKs are therefore an attractive therapeutic target for RA and other inflammatory diseases.6