Fig. 3

Dll4 allele deletion affects VEGF/VEGFR signaling and the regulators of vascular smooth muscle cell recruitment. a Average serum level of VEGF, VEGFR1, VEGFR2 measured by ELISA and VEGFR2/VEGFR1 (R2/R1) ratio in WT and Dll4^+/− mice. Between two experimental groups, only VEGFR2/VEGFR1 ratio (R2/R1) differs with statistical significance. b VEGFR2 immunostaining showing increased expression of this VEGF-A receptor in Dll4^+/− vs. control tumors. c Differential gene expression in WT vs. Dll4^+/− papillomas determined by quantitative RT-PCR analyses. d Double PECAM/PDGFR-β immunostaining showing reduced PDGFR-β+ vascular coverage and indicating reduced Pdgfr-β expression in the vasculature of Dll4^+/− vs. WT papillomas