 | This articleneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Growth factor" – news ·newspapers ·books ·scholar ·JSTOR(February 2014) (Learn how and when to remove this message) |
Agrowth factor is a naturally occurring substance capable of stimulatingcell proliferation,wound healing, and occasionallycellular differentiation.[1] Usually it is a secretedprotein or asteroid hormone.
Growth factor is sometimes used interchangeably among scientists with the termcytokine.[2] Historically, cytokines were associated withhematopoietic (blood and lymph forming) cells andimmune system cells (e.g.,lymphocytes and tissue cells fromspleen,thymus, andlymph nodes). For thecirculatory system andbone marrow in which cells can occur in a liquid suspension and not bound up in solidtissue, it makes sense for them to communicate by soluble, circulating proteinmolecules. However, as different lines of research converged, it became clear that some of the same signaling proteins which the hematopoietic and immune systems use were also being used by all sorts of other cells and tissues, during development and in the mature organism.
Whilegrowth factor implies a positive effect oncell proliferation,cytokine is a neutral term with respect to whether a molecule affects proliferation. While some cytokines can be growth factors, such asG-CSF andGM-CSF, others have an inhibitory effect oncell growth or cell proliferation. Some cytokines, such asFas ligand, are used as "death" signals; they cause target cells to undergo programmedcell death orapoptosis.
 |
| This sectiondoes notcite anysources. Please helpimprove this section byadding citations to reliable sources. Unsourced material may be challenged andremoved. Find sources: "Growth factor" – news ·newspapers ·books ·scholar ·JSTOR(August 2025) (Learn how and when to remove this message) |
Individual growth factor proteins tend to occur as members of larger families of structurally andevolutionarily related proteins. There are many families, some of which are listed below:
Thealpha granules in bloodplatelets contain growth factors PDGF, IGF-1, EGF, and TGF-β which begin healing of wounds by attracting and activatingmacrophages,fibroblasts, andendothelial cells.
For the last two decades, growth factors have been increasingly used in the treatment ofhematologic andoncologic diseases[3][4] and cardiovascular diseases[5][6] such as:
