INSULIN-LIKE GROWTH-FACTORS AND THEIR RECEPTORS AS GROWTH-REGULATORS IN NORMAL PHYSIOLOGY AND PATHOLOGICAL STATES

Insulinlike growth factors (IGFs), their binding proteins, and receptors are expressed by many different tissues, suggesting that they may act as parts of an autocrine-paracrine system in addition to having a classic endocrine role. Since these growth factors are essential for the normal growth and development of the organism, their altered rate of production in a number of important disease states results in severe growth alterations. These include nutritional deprivation, growth hormone deficiency, diabetes, and malignancy.