KLF2 and KLF4 gene ablation decreases eNOS mRNA expression in E9.5 embryos. A) qRT-PCR revealed that eNOS mRNA was reduced in E9.5 KLF2-/-KLF4+/- and KLF2-/-KLF4-/- embryos compared to KLF2-/- (p = 0.0078 and p = 0.0077, respectively) and WT (p = 0.0008 and p = 0.0009, respectively) embryos of the same age. B) VEGFR2 mRNA is significantly reduced in KLF2-/-KLF4+/- and KLF2-/-KLF4-/- compared to WT (p = 0.0021 and p = 0.0041, respectively) but not KLF2-/-. C) Occludin mRNA is also significantly reduced in KLF2-/-KLF4+/- and KLF2-/-KLF4-/- compared to WT (p = 0.0167 and p = 0.011, respectively) and KLF2-/- (p = 0.013 and p = 0.016, respectively). D) Endothelin, E) Thrombomodulin-1 and F) PECAM1 mRNA amounts are not significantly different in KLF2-/-KLF4-/- and KLF2-/-KLF4+/- compared to WT and single knockout embryos. n = 3 for each genotype.