Insulin-like growth factor 1 （IGF-1） is also known as somatomedin C,
IGF1A, IGFI, sulfation factor, and is a hormone similar in molecular structure
to insulin. IGF-1 Protein binds to cell surface receptor IGF type 1 receptor,
which abbreviated as "IGF1R" and modulates growth in many tissues,
such as nervous tissue, lymphoid tissue, reproductive tissue, smooth muscle,
endothelium, and bone. IGF-1 Protein also mediates neuroprotective mechanism.
It is produced primarily by the liver as an endocrine hormone as well as in
target tissues in a paracrine/autocrine fashion. IGF-1 consists of 70 amino
acids in a single chain with three intramolecular disulfide bridges. IGF-1 has
a molecular weight of 7649 daltons.