The IGF-I R protein is a receptor tyrosine kinase that mediates the effects of insulin-like growth factor 1 (IGF1) and has high affinity for IGF1. Upon ligand binding, IGF1R is activated, leading to autophosphorylation and tyrosine phosphorylation of substrates, including IRS1/2, Shc, and 14-3-3 proteins. IGF-I R Protein, Mouse (HEK293, His) is the recombinant mouse-derived IGF-I R protein, expressed by HEK293 , with C-His labeled tag.