Molecular aspects of insulin-like growth factors, their binding proteins and receptors.

As we have tried to illustrate in the preceding brief review of some of the current research on the molecular biology of the IGF system, the physiological function of these important and pluripotent molecules will undoubtedly prove to be extraordinarily complex. This prediction is based upon the extensive heterogeneity of the IGF-I and IGF-II ligands themselves, the multiplicity of BPs which may influence IGF action either positively or negatively at numerous levels, and the ability of these hormones/growth factors (and possibly their BPs) to interact with disparate receptor moieties, both singly and in concert, in order to elicit their various effects.