Figure 2

IGF1 availability was regulated by cell-mediated ligand depletion and IGFBP sequestration. A, IGF1 was depleted by OVCAR5 in the absence of IGFBPs. B, The majority of IGF1 added to conditioned media was sequestered by cell-secreted IGFBPs. *indicates significant difference (p < 0.05) from cell-free control for A or from serum-free media control for B, n = 3 per treatment.