Interleukin-8 (IL-8) is encoded by the IL8 gene and produced by macrophages and other cell types such as epithelial cells. It is also synthesized by endothelial cells, which store IL-8 in their storage vesicles. There are many receptors capable to bind IL-8, the most affinity to IL-8 are receptors CXCR1, and CXCR2. As a member of the CXC chemokine family, function of IL-8 is the induction of chemotaxis in its target cells, like neutrophil granulocytes, basophils, and T-cells. Rhesus macaque IL-8 has approximately 94 % amino acid sequence identity with human IL-8.