Growth factors

This collective term originally referred to substances that promote cell growth. It is used rather loosely now, comprising molecules that function as growth stimulators (mitogens) but also as growth inhibitors (sometimes referred to as negative growth factors ), factors that stimulate cell migration (see: Motogenic cytokines ) or function as chemotactic agents (see also: Chemotaxis ) or inhibit cell migration or invasion of tumor cells, factors that modulate differentiated functions of cells, factors involved in apoptosis , or factors that promote survival of cells without influencing growth and differentiation.

Such factors can be secreted diffusible factors and can also exist in membrane-anchored forms. They can, therefore, act in an autocrine , paracrine , juxtacrine or retrocrine manner.

In many instances the term is used as a synonym for Cytokines . See also: Recombinant cytokines . See also: Minicytokines . For other entries pertaining to cell death by apoptosis see also: Apoptosis MiniCOPE Dictionary .