Interleukin 8 (IL-8), like IL-6, is secreted by macrophages and a variety of cells that express Toll-like receptors in response to the stimulation of pathogens. IL-8's primary function is to recruit neutrophils and other target cells through chemotaxis to the infected site to eliminate pathogens. IL-8 causes increased intracellular Ca2+, release of reactive oxygen species, and other physiological changes required for migration and phagocytosis. IL-8 is also known to promote angiogenesis.