protein_function: Involved in the Notch signaling pathway as Notch ligand.Activates NOTCH1 and NOTCH4. Involved in angiogenesis; negativelyregulates endothelial cell proliferation and migration andangiogenic sprouting. Essential for retinal progenitorproliferation is required for suppressing rod fates in lateretinal progenitors as well as for proper generation of otherretinal cell types. During spinal cord neurogenesis, inhibits V2ainterneuron fate..
Delta like ligand 4 is a protein that in humans is encoded by the DLL4 gene. It is mapped to 15q15.1. This gene is a homolog of the Drosophila delta gene. DLL4 is a transmembrane ligand for Notch receptors that shows restricted expression to endothelial cells (ECs), in particular to arteries and capillaries, and is involved in vascular development, and it also appeared to be a major trigger of Notch receptor activities previously implicated in arterial and vascular development. Mouse DLL4 could activate mouse Notch1 and mouse Notch4. DLL4 acts as a negative regulator of tumor angiogenesis, its blockade results in the striking uncoupling of tumor growth from vessel density, presenting a novel therapeutic approach even for tumors resistant to anti-VEGF therapies. In addition to it, this gene also plays an important role in promoting Th17 effector activity during mycobacterial challenge.