CXCL5 is a member of the CXC family of chemokines also known as epithelial activated peptide 78 (ENA-78). The precursor of CXCL5 contains 114 amino acids, with a signal peptide of 36 amino acids which is cleaved to generate the 78 amino acid mature protein (8 kD). CXCL5 is expressed by monocytes/macrophages, endothelial cells, vascular smooth muscle cells, epithilial cells, and eosinophils. CXCL5 is an inflammatory cytokine which binds to the cell surface receptor CXCR2 and induces chemotaxis of neutrophils to a target site. High levels of CXCL5 have been associated with prostate, gastric, and pancreatic cancer progression.