OSM (oncostatin M) is a pleiotropic cytokine that functions as a key regulator of inflammatory responses and tissue remodeling. OSM binds to heterodimeric receptors composed of gp130 paired with either OSMR or LIFR, activating multiple signaling pathways including JAK/STAT, MAPK, and PI3K/AKT 1. The cytokine demonstrates dual effects on cell proliferation, initially identified as an inhibitor of melanoma and solid tumor cell lines while stimulating proliferation of other cell types 2. OSM plays critical roles in inflammatory diseases, particularly inflammatory bowel disease (IBD), where it is highly expressed in inflamed intestinal tissues and correlates with disease severity 3. The cytokine promotes inflammation by inducing proinflammatory molecules including IL-6, ICAM1, and chemokines (CCL2, CXCL9-11) from stromal cells 34. In the tumor microenvironment, OSM facilitates cancer progression by reprogramming fibroblasts to secrete VEGF and chemokines, enhancing myeloid cell recruitment 5. Additionally, OSM contributes to tissue regeneration by promoting angiogenesis through macrophage-fibroblast communication 6. High OSM expression serves as a biomarker for anti-TNF therapy resistance in IBD patients, highlighting its clinical significance 3.