Immune and inflammatory responses are rightly regulated to maintain a homoeostatic balance between an effective immune response and tissue damage to the host. Nitric Oxide is the principal mediator of many of the cytokine-inducible macrophage activities during a normal cell-mediated immune response. STK (Stem Cell-Derived Tyrosine Kinase), the murine homolog of the human RON (RON Protein Tyrosine Kinase/ Receptor d’origine nantais), is expressed on murine resident peritoneal macrophages. The ligand for STK, MSP (Macrophage Stimulating Protein), is a serum protein that is activated by members of the Coagulation Cascade (Tissue Clotting Factors) in response to tissue damage. MSP has an inhibitory effect on the production of Nitric Oxide by activated peritoneal macrophages. STK receptor suppresses Nitric Oxide production, therefore ameliorating [...]