IGF-I and -II signal through the IGF-I Receptor, which is homologous to the Insulin Receptor. The high-affinity IGF-II Receptor does not play a direct role in signaling, but regulates the concentration of free IGF-II. The IGFs are involved in skeleta
There are two kinds of IGF receptors based on their relative affinities for IGF1 versus IGF2. The IGF1 receptor prefers IGF1 over IGF2 and weakly binds insulin. IGF1 receptor is a disulfide-linked heterotetrameric transmembrane protein consisting of