In RA, Janus Kinases (JAKs) regulate most of the cytokines. JAK1,2,3 and Tyk2 are phosphorylated and signal transduce the activators of transcription (STATs). JAKs are a target for RA and are successfully used in treatment to block JAK1,2,3. STAT1 and -3 are good predictors of a clinical response, when decreased a favourable outcome can be found. Those two STATs play a role in IFN and IL-6 signalling