SCDGFB (Spinal cord derived growth factor B) is a member of the platelet derived growth factor family. It only forms homodimers and does not dimerize with the other three family members. It is a potent mitogen for cells of mesenchymal origin. It is activated by proteolytic cleavage and this active form acts as a specific ligand for beta platelet derived growth factor receptor. It is released by platelets upon wounding and plays an important role in stimulating adjacent cells to grow and the