Q9NR61

Delta-like ligand 4 (DLL4), also know as Delta-4, is a homologue of the Drosophila delta protein, and functions as a transmembrane bound ligand to the notch receptor Notch1. DLL4 is expressed in the vasculature and plays a critical role in vascular development. It is induced by vascular endothelial growth factor (VEGF), as a negative feedback regulator to regulate angiogenic sprouting and promote the formulation of a differentiated vascular network. DLL4 has been found to be strongly expressed in tumor vessels of clear-cell renal tumors and bladder cancer, and inhibition of DLL4 results in increased vascular proliferation but defective maturation. This in turn leads to a decrease in tumor growth, with no apparent toxicity.