IL-8 is a member of the chemokine family. Chemokines are small secreted molecules containing 4 conserved cysteine residues and 2 disulfide linkages. IL-8 is a member of the CXC family of chemokines and is also known as CXCL8. IL-8 is predominantly produced by monocytes, T cells, NK cells and neutrophils and its expression is induced by IL-1 and TNF, as well as bacterial and viral products.

IL-8 promotes the migration of leukocytes including neutrophils, monocytes, T and Blymphocytes and basophils to the site of an infection to facilitate an immune response. Additionally, IL-8 promotes the adhesion and transmigration of neutrophils across the endothelium into tissues. IL-8 also exhibits chemotactic properties for non-leukocyte cell types such as keratinocytes, and smooth muscle cells as well as inducing the proliferation and chemotaxis of endothelial cells suggests it plays a role in angiogenesis.