Oncostatin M (OSM)  is a multifunctional cytokine, and belongs to Interleukin-6 (IL-6) subfamily, which also includes IL-11, leukemia inhibitory factor (LIF), ciliary neurotropic factor, cardiotrophin-1, and novel neurotropin-1. In vivo,  OSM is secreted from activated T cells, monocytes, neutrophils, and endothelial cells. OSM is related to LIF, and shares a receptor with LIF in human. Human OSM can bind to gp130 and recruit OSM Receptor β or LIF Receptor β to form a ternary complex. OSM stimulates the growth of different types of cells, including megakaryocytes, fibroblasts, vascular endothelial cells, and T cells. OSM inhibits the proliferation of several cancer cell lines, such as solid tissue tumor cells, lung cancer cells, melanoma cells, and breast cancer cells. 
Recombinant human Oncostatin M(209 a.a.) (rhOSM)  produced in  E. coli is a single non-glycosylated polypeptide chain containing 210 amino acids. A fully biologically active molecule, rhOSM has a molecular mass of 23.8 kDa analyzed by reducing SDS-PAGE and is obtained by proprietary chromatographic techniques at ExCell Bio.