Description_x000D_ Biochem/physiol Actions_x000D_ Oncostatin M (OSM), LIF, G-CSF, IL-6, and CNTF are structurally related members of the same cytokine family sharing similarities in their primary amino acid sequences, predicted secondary structure, and receptor components. OSM is a growth-regulating cytokine, affecting a number of tumor and normal cells. This material was first identified by its ability to inhibit the growth of A375 melanoma cells and other human tumor cells, but not inhibit the growth of normal human fibroblasts. It acts synergistically with TGF β1 to inhibit the proliferation of tumor cells like A375 melanoma cells. It induces an increase in LDL receptor expression and LDL uptake by hepatoma cells. OSM activates synovial fibroblast-like cells to produce urokinase type plasminogen activator. OSM is secreted by macrophages and activated T lymphocytes._x000D_ Analysis Note_x000D_ The specific activity was determined by the dose-dependent stimulation of the proliferation of human TF-1 cells (human erythroleukemic indicator cell line)._x000D_ Legal Information_x000D_ HumanKine is a registered trademark of HumanZyme Inc.