TYK2 (tyrosine kinase 2) is a non-receptor tyrosine kinase that plays critical roles in cytokine and interferon signaling pathways, particularly those mediated by type I interferons, IL-12, IL-23, and IL-10 1. The protein functions by associating with heterodimeric cytokine receptor complexes and activating STAT family transcription factors (STAT1, STAT3, STAT4, STAT6) through phosphorylation, ultimately regulating immune responses and cell development 1. TYK2 is essential for proper immune function, as genetic variants in the TYK2 locus are associated with autoimmune diseases including systemic lupus erythematosus, psoriasis, and dermatomyositis 12. Loss-of-function mutations can cause primary immunodeficiency (hyper-IgE syndrome) characterized by recurrent infections and elevated IgE levels 3. Conversely, TYK2 inhibition shows therapeutic promise for autoimmune conditions, with selective TYK2 inhibitors like deucravacitinib approved for psoriasis treatment and showing efficacy in other inflammatory diseases 14. Notably, TYK2 inhibition enhances regulatory T cell function while blocking pathogenic Th1/Th17 responses, providing a unique therapeutic profile distinct from other JAK inhibitors 5. TYK2 also regulates pancreatic β-cell development and interferon responses, linking it to type 1 diabetes pathogenesis 6.