Insulin-like Growth Factor Binding Protein-3 (IGFBP-3) is the primary binding protein for Insulin-like Growth Factor-1 (IGF-1) in human serum. Over 90% of circulating IGF-1 is bound to IGFBP-3, forming a complex that extends the half-life of IGF-1 and modulates its accessibility to target tissues. Produced mainly by the liver, IGFBP-3 plays a crucial role in regulating the bioavailability and activity of IGF-1, which is a key mediator of growth hormone action and various cellular processes, including cell growth, differentiation, and metabolism.
IGFBP-3
IGF transport protein.