TYK2 and psoriasis: Tyrosine kinase 2 (TYK2) is an intracellular enzyme that mediates cytokine signaling (e.g., interleukin [IL] 23, IL‐12, type I interferons); IL‐23 and type I interferons are involved in psoriasis pathogenesis.7, 8 Deucravacitinib, an oral, selective, allosteric TYK2 inhibitor, uniquely binds to the less conserved regulatory (pseudokinase) domain of TYK2 rather than to the more conserved catalytic domain where Janus kinase (JAK) type 1, 2, and 3 inhibitors bind,7, 9 driving its selectivity and representing the first in a new class of oral drugs.