Despite these advantages, some of the major cytokines involved in RA pathogenesis, specifically TNF-α, IL-1 and IL-17, are not dependent on JAKs for their signalling.52–54 Whether or not combination therapy, for example with a jakinib and TNF inhibitor, will show benefit over a jakinib or TNF inhibitor alone awaits appropriate testing. Here, IL17A is linked to rheumatoid arthritis.