EDIL3 is a glycoprotein that is secreted by endothelial cells and can associate with the endothelial cell surface and the extracellular matrix. EDIL3 is regulated by hypoxia or vascular injury and has been implicated in vascular remodeling during angiogenesis.The predicted 480-amino acid mouse and human proteins, which are 95% identical, contain a signal peptide, 3 epidermal growth factor (EGF)-like repeats, and 2 discoidin I-like repeats. Northern blot analysis revealed expression of a 6.5-kb transcript in highly vascularized mouse embryonic day-15.5 tissue and in mouse and human endothelial cells, but not in other adult tissues. In situ hybridization analysis showed Del1 expression in developing endocardium at 9.5 days postcoitus and in renal artery and hypertrophic chondrocytes at 13.5 days postcoitus.