IL19 is a cytokine belonging to the IL-10 family that functions primarily as an anti-inflammatory mediator with tissue-protective properties 1. IL19 exerts its biological effects through binding to a heterodimeric receptor complex consisting of IL-20RA and IL-20RB subunits, subsequently activating JAK/STAT signaling pathways, particularly STAT3 2. In immune regulation, IL19 promotes anti-inflammatory responses by polarizing T-helper cells toward a Th2 phenotype and is involved in maintaining tissue epithelial integrity 1. However, IL19 demonstrates context-dependent functions across different disease states. In atopic dermatitis, IL19 is highly expressed in inflammatory keratinocyte subpopulations and contributes to skin barrier disruption and inflammatory responses 34. In cancer, IL19 plays a protumorigenic role, particularly in bone metastasis where osteoclast-derived IL19 promotes tumor cell proliferation through IL-20RB/JAK1/STAT3 signaling 2. In glioblastoma, elevated IL19 expression correlates with poor survival and promotes immunosuppression by reprogramming tumor-associated macrophages and enhancing tumor invasion 5. IL19 also contributes to chr1 rhinosinusitis pathogenesis and hepatocellular carcinoma development 67, highlighting its diverse pathological roles beyond its canonical anti-inflammatory function.