TGFβ1 and BMP-9 have opposite effects on VEGF expression. BAECs were treated with combinations of TGFβ1 (1 ng/mL), BMP-9 (10 ng/mL), the ALK5 inhibitor SB-4311542 (5 μM), the BMP-9 inhibitor ALK1/Fc (200 ng/mL), and the VEGFR2 inhibitor SU1498 (10 μM) for 24 hours. VEGF expression was determined by real-time PCR and immunoblotting of VEGF from the media (A). Cell proliferation was determined by ³H-thymidine incorporation (B). Cell migration was determined by migration assays (C), and tube formation was determined on Matrigel (D); images were obtained 6 hours after plating. Asterisks indicate statistically significant differences compared with control (no treatment). **P < .01; ***P < .001; Tukey test.