Tyk 2 belongs to the family of non-receptor janus tyrosine kinases, which regulate a spectrum of cellular functions occurring downstream of activated cytokine receptors in the lympho-hematopoietic system. Immunological stimuli, such as interferons and cytokines, recruit STAT transcription factors to the cytokine receptor where Tyk 2 is associated. Tyk 2 then phosphorylates proximal STAT factors, which subsequently dimerize, translocate to the nucleus, and bind to cis elements upstream of target gene promoters to regulating transcription. The canonical JAK-STAT pathway is integral to maintaining a normal immune system by stimulating proliferation, differentiation, survival, and host resistance to pathogens. Cytokine induced pro-inflammatory responses are attractive targets for anti-inflammatory therapies, specifically at the level of Jak-STAT signaling.