Silencing VEGFA inhibits the formation of tubules in HUVECs when grown on a Matrigel matrix. To investigate the pro-angiogenic potential of compound C1, HUVECs treated with C1 were differentiated on a Matrigel support. These studies showed that treatment with C1 stimulated angiogenesis by increasing tubule branching density. Furthermore, a stable HUVEC cell line was generated to ablate Vegfa mRNA via expression of a short hairpin (sh)RNA targeting this transcript. The shRNA expressing cell line had reduced ability to differentiate into tubules as the number of tubules was reduced by >60% as compared to wild type, non-shRNA expressing cells (Fig. ).