Human Chemokine (C-X-C motif) Ligand 7 (CXCL7), also known as neutrophil activating peptide 2 (NAP-2), is a member of the CXC chemokines containing an ELR domain (Glu-Leu-Arg tripeptide motif). Similar to other ELR domain containing CXC chemokines, such as IL-8 and the GRO proteins, CXCL7 binds CXCR2, chemoattracts and activates neutrophils. CXCL7, Connective Tissue Activating Protein III (CTAPIII) and βthrombogulin (βTG), are proteolytically processed carboxylterminal fragments of platelet basic protein (PBP) which is found in the alphagranules of human platelets. Although CTAPIII, βTG, and PBP represent amino-terminal extended variants of NAP2 and possess the same CXC chemokine domains, these proteins do not exhibit CXCL7/NAP2 activity. CXCL7 induces cell migration through the G-protein-linked receptor CXCR-2.