E-selectin ligand (None universally standardized; sometimes abbreviated contextually as "ESL" for E-selectin ligand or with protein names (e.g., PSGL-1, ESL-1, CD44) for individual ligands)

E-selectin ligands are not a single molecular target but a heterogeneous group of glycoproteins and glycoconjugates present on the surface of leukocytes and certain tumor cells that mediate their binding to E-selectin during processes such as inflammation, immune cell trafficking, and metastasis. The major well-characterized E-selectin ligands on leukocytes are P-selectin glycoprotein ligand-1 (PSGL-1), E-selectin ligand-1 (ESL-1), and CD44, each carrying specific sialylated and fucosylated carbohydrate modifications (notably sialyl-Lewis^X^ motifs) that are required for E-selectin binding. These ligands are responsible for the "rolling" stage of leukocyte extravasation across blood vessel walls by interacting with E-selectin expressed on activated endothelium. Because "E-selectin ligands" refer to a functional and biochemical class rather than a single gene or protein, this is not a distinct, unambiguous therapeutic target but rather a collection of molecular structures and modifications mediating similar biological roles.

Other names

E-selectin binding ligandESLP-selectin glycoprotein ligand-1 (PSGL-1)E-selectin ligand-1 (ESL-1, also MGF-160, CFR-1)CD44Sialyl-Lewis X-carrying glycoproteinsGlycoconjugates bearing Lewis X/A antigens

Inhibition of E-selectin–ligand interaction to block leukocyte adhesion, rolling, and transmigration during inflammatory responses and tissue infiltration in disease