High affinity insulin-like growth factor-1 binding protein (IGFBP) inhibitor (Ki values are 1 - 24 nM for all six human subtypes). Displaces insulin-like growth factor-1 (IGF-1) from the IGF-1:IGFBP complex and suppresses IGF1-induced proliferation of 3T3 fibroblasts. Also increases cardiomyocyte proliferation in vivo. Purity 98%. MW (observed): 341.27