Purity >95% as determined by SDS-PAGE. Interleukin 8 (IL-8 or CXCL8) is a member of the CXC cytokine family and is produced by macrophages, epithelial, smooth muscle, and endothelial cells. IL-8 binds the G protein-coupled serpentine receptors CXCR1 and CXCR2. IL-8 recruits innate immune cells, induces phagocytosis, and stimulate angiogenesis.