Figure 4From: Novel insights into the differential functions of Notch ligands in vascular formationMaintenance of arterial identity mediated by Dll1-Notch signaling. At a later stage of development, Dll1 expression is induced in arterial endothelial cells and is required for maintenance of the arterial phenotype. Dll1 also acts upstream of VEGF by regulating the expression of VEGFR2 and its co-receptor neuropilin 1 (Nrp1).Back to article page