 Cytokines IL-4 and IL-13 gets elevated in lungs of chronically suffered asthmatics.Signalling through IL-4/IL-13 complexes is thought to occur through IL-4Rα-chain, which is responsible for activation of JAK-1 and Tyk2 kinases.A role of Tyk2 in rheumatoid arthritis is directly observed in Tyk2-deficient mice that were resistant to experimental arthritis.