Effect of dominant-negative ELF-1 peptide on endothelial gene expression. (A) Quantitative RT-PCR of Tie2, Tie1, eNOS, Flk1, and Flt1 at baseline in HUVECs, and after administration of peptide A1 and mutant peptide A1. Experiments were performed in triplicate and represent means ± SE. (B) Western blot analysis of Tie2, eNOS, and Flk1 expression in HUVECs at baseline (control), at different concentrations (μM) of the mutant peptide A1 (Mut A1) and peptide A1.