====== Growth factor ======
A growth [[factor]] is a naturally occurring substance capable of stimulating cellular growth, proliferation, healing, and cellular differentiation. Usually it is a protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes.

Growth factors typically act as signaling molecules between cells. Examples are cytokines and hormones that bind to specific receptors on the surface of their target cells.

{{ ::signaling_pathway.jpg?400|}}

They often promote cell differentiation and maturation, which varies between growth factors. For example, bone morphogenetic proteins stimulate bone cell differentiation, while [[fibroblast growth factor]]s and [[vascular endothelial growth factor]]s stimulate blood vessel differentiation (angiogenesis).

Growth factors and inflammatory [[cytokine]]s activate the [[mitogen activated protein kinase]] (MAPK) cascade.

see [[Angiogenic factor]]

see [[Epidermal growth factor]]

see [[Fibroblast growth factor]]

see [[Hepatocyte growth factor]]

see [[Platelet-derived growth factor]]

see [[Transforming growth factor]] (TGF)