Insulin-like growth factors and their receptors in normal physiology and pathological states.

The insulin-like growth factor system, which includes the IGFs, IGF-binding proteins and IGF receptors, plays an essential role in normal growth and development, as well as the cellular differentiation of a number of other important systems, including the reproductive and immune systems. IGF action has also been implicated in several pathological conditions, including tissue repair, malnutrition, diabetes and malignancy.