IGF-1
IGF-1 or somatomedin C, is a growth factor, synthesised primarily by the liver under the influence of GH, of which it is the principal mediator. 95 % of IGF-1 circulates bound to binding proteins (the IGF-BPs), in particular IGF-BP3. Its assay constitutes an important diagnostic and prognostic tool in investigations of acromegaly or of a GH deficit.