growth factor

growth factor n a substance (as a vitamin B₁₂ or an interleukin) that promotes growth and esp. cellular growth

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any of various chemicals, particularly polypeptides, that have a variety of important roles in the stimulation of new cell growth and cell maintenance. They bind to the cell surface on receptors. Specific growth factors can cause new cell proliferation (epidermal growth factor, haemopoietic growth factor) and the migration of cells (fibroblast growth factor) and play a role in wound healing (platelet-derived growth factor; PDGF). Some growth factors act in the embryonic stage of development; for example, nerve growth factor. It is thought that some growth factors that induce cell proliferation are involved in the abnormal regulation of growth seen in cancer when produced in excessive amounts (e.g. insulin-like growth factor, IGF-I). Growth factors produced locally around a carcinoma (e.g. vascular endothelial growth factor) are important in the encouragement of invasion by the tumour; other factors (e.g. autocrine motility factor, migration-stimulating factor) are also significant. See also bone growth factor.

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any of numerous substances that promote normal or pathological growth of cells or tissue, including the epidermal growth factors, insulin-like growth factors, nerve growth factors, platelet-derived growth factors, and transforming growth factors.