DLL4 (Delta-like 4) is one of five ligands of Notch receptors. It is up-regulated at sites of physiological and pathological angiogenesis, whereas its expression is low in most adult normal tissues. It is also highly expressed in human clear-cell renal carcinomas, bladder cancers, and breast cancers. Blocking the DLL4-Notch interaction seems to be a promissing therapeutic approach.
