The leukocyte adhesion to endothelium is pivotal in leukocyte recruitment which takes place during inflammatory, autoimmune and infectious conditions. The interaction between leukocytes and endothelium requires an array of adhesion molecules expressed on leukocytes and endothelial cells, thereby promoting leukocyte recruitment into sites of inflammation and tissue injury. Intervention with the adhesion molecules provides a platform for development of anti-inflammatory therapeutics. This review will focus on developmental endothelial locus-1 (Del-1), an endogenous inhibitor of leukocyte adhesion.