The Interleukins belong to the family termed cytokines. They are peptides used by immune and inflammatory cells to communicate and control cell operations. 

The cytokines have some similar actions to the Growth Factors but Growth Factors regulate proliferation of non-immune cells. Interleukin-8 is a glycoprotein produced primarily by macrophages and monocytes. Its primary target cells are neutrophils. 

Interleukin-8 is a chemotactic agent for monocytes and neutrophils. Interleukin 8 causes oxygen radical and enzyme release by neutrophils and mobilizes products into circulation. Interleukin 8 is stimulated by Interleukin 1 and Tumor Necrosis Factor.

Interleukin 8 (IL-8) is a promising marker for many clinical conditions and currently being applied by various subspecialties of medicine either for the purpose of rapid diagnosis or as a predictor of prognosis. Nevertheless, IL-8 level increased as a result of many inflammatory conditions, so careful interpretation of IL-8 level is required to make correlation with desired clinical condition's diagnosis or prognosis.

IL-8 is involved in neutrophil activation, and is released from several cell types in response to inflammation, including monocytes, macrophages, neutrophils, and intestine, kidney, placenta, and bone marrow cells. It is a member of the beta-thromboglobulin superfamily and is structurally related to platelet factor 4. IL-8 is involved in mitogenesis, inhibition of angiogenesis, inflammation, chemotaxis, neutrophil degranulation, leukocyte activation, and calcium homeostasis.

Promising use of interleukin 8 (IL-8) in various fields of medicine:

References:

- https://intarchmed.biomedcentral.com/articles/10.1186/1755-7682-3-11

- https://www.sciencedirect.com/science/article/pii/B9780080552323619166

- https://www.frontiersin.org/articles/10.3389/fimmu.2020.602395/full