interleukin

Interleukins are a group of cytokines (secreted signaling molecules) that were first seen to be expressed by white blood cells (leukocytes, hence the -leukin) as a means of communication (inter-). The name is something of a relic though (the term was coined by Dr. Paetkau, University of Victoria); it has since been found that interleukins are produced by a wide variety of bodily cells. The function of the immune system depends in a large part on interleukins, and rare deficiencies of a number of them have been described, all featuring autoimmune diseases or immune deficiency.
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Interleukin /in·ter·leu·kin/ a generic term for a group of multifunctional cytokines that are produced by a variety of lymphoid and nonlymphoid [more]Interleukin - Community and Resources

Noun
1. any of several lymphokines that promote macrophages and killer T cells and B cells and other components of the immune system
(hypernym) lymphokine

[in-ter-LOO-kin]
A biological response modifier (substance that can improve the body's natural response to infection and disease) that helps the immune system fight infection and cancer. These substances are normally produced by the body. They are also made in the laboratory for use in treating cancer and other diseases.

Any of a class of protein-carbohydrate compounds that function as immune-system regulators.