Abstract: As a chronic, immune-mediated in-flammatory disease, plaque psoriasis has a great burden of disease and influences on patient's physi-cal and mental health. In the past decade, plaque psoriasis treatment with biological agents achieved breakthrough development, while oral drugs with promising efficacy and safety are yet to be met. By cell signal transduction, the Janus kinase-signal transducer and activator of transcription pathway plays an important role in numerous immune-relat-ed diseases. Tyrosine kinase 2 (TYK2), a member of the JAK family, can impact on plaque psoriasis by regulating signaling and functional responses down-stream of IL-12, IL-23, IFN. Deucravacitinib, a highly selective TYK2 inhibitor, has finished its phase 3 clinical trials and shown its efficacy and safety in treatment of plaque psoriasis. Several kinds of TYK2 inhibitors are under research and develop-ment at the moment. In this review, we demon-strate roles of JAK-STAT pathway and TYK2 in plaque psoriasis as well as updates on ongoing and recently completed trials of TYK2 inhibitors. 

Key words: plaque psoriasis, JAK-STAT pathway, tyrosine kinase 2 inhibitor