Insulin Like Growth Factors 1 (IGF-I) is a 7.79 kDa member of the Insulin-like Growth Factors with 71 amino acid residues. IGF-I is mainly expressed from liver, adipose tissue, cervi, endometrial stromal cells, leydig cells, and can be isolated from plasma. IGF-I is mediating the protein anabolic and promoting effect of pituitary growth hormone. IGF-I also affects metabolism of glycogen, DNA synthesis and glucose uptake via binding to IGF-I receptor.