PF-06454589 is a potent and selective allosteric inhibitor of TYK2 (Tyrosine Kinase 2), a non-receptor tyrosine kinase involved in immune signaling pathways. It is primarily utilized in pharmaceutical research and development for its potential therapeutic applications in autoimmune and inflammatory diseases, such as psoriasis, rheumatoid arthritis, and inflammatory bowel disease. By specifically targeting the pseudokinase domain of TYK2, it modulates signaling through cytokines like IL-12, IL-23, and type I interferons without broadly affecting other JAK family members. Ongoing preclinical and clinical studies are evaluating its efficacy, safety, pharmacokinetics, and potential for clinical use in humans.