Growth factor is any of about twenty small proteins that attach to specific receptors on the surface of stem cells in bone marrow and promote differentiation and maturation of these cells into morphotic constituents of blood.

The most important growth factors are :

• granulocyte-colony stimulating factor (G-CSF)
• granulocyte-macrophage colony stimulating factor (GM-CSF)
• platelet-derived growth factor (PDGF)
• erythropoietin (EPO)
• thrombopoietin (TPO)
• myostatin (GDF-8)

For the last two decades growth factors have been increasingly used in treatment of hematologic and oncologic diseases like :

• granulocytopenia
• myelodysplastic syndrome (MDS)
• leukemias
• aplastic anaemia
• bone marrow transplantation