It is known that an anti-angiogenic compound AGM-1470 inhibits cells in vitro and in vivo, on mitogen-induced cell growth in capillary endothelial cells. In monolayer cultures, 1 ng/ml AGM-1470 completely inhibited both basic fibroblast growth factor (bFGF) induced cell growth and vascular endothelial growth factor (VEGF) induced cell growth in a cytostatic manner. IC50 was 85 pg/ml and 55 pg/ml for bFGF and VEGF induced cell growth, respectively. Moreover, in collagen gels, AGM-1470 suppressed the colony formation induced by bFGF and by VEGF in a dose dependent manner. Few colonies appeared 25 days after co-culuture with I ng/ml AGM-1470 and either 1 ng/ml bFGF or 5 ng/ml VEGF. It is suggested that a potent; inhibition of growth signals of more than one growth factor for endothelial cells might be involved in anti-angiogenic activity of AGM-1470.