cytokine

American  

[sahy-tuh-kahyn] / ˈsaɪ təˌkaɪn /

noun

1. a type of small protein, as interferon, secreted by certain cells, especially immune cells, that helps regulate the body’s immune response to inflammation and disease: The largest group of cytokines that stimulate immune cell proliferation are the interleukins.

   Cytokines are like the body’s messenger system for mobilizing its response to pathogens.

   The largest group of cytokines that stimulate immune cell proliferation are the interleukins.

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cytokine British  

/ ˈsaɪtəʊˌkaɪn /

noun

1. any of various proteins, secreted by cells, that carry signals to neighbouring cells. Cytokines include interferon

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cytokine Scientific  

/ sī′tə-kīn′ /

1. Any of several regulatory proteins, such as the interleukins and lymphokines, that are released by cells of the immune system and act as intercellular mediators in the generation of an immune response.

2. Also called chemokine

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Usage

What is a cytokine? A cytokine is a type of protein released by cells in the body to carry messages to other cells. These messages tell the cells to do something, like to start an immune response. Cytokines get triggered by the presence of an antigen, which is any substance, such as a bacterium or virus, that causes the body to produce antibodies. There are many different types of cytokines. Common types are interleukins and lymphokines, which include the cytokines known as interferons. Cytokines play an important role in many different processes, including the regulation of inflammation and the immune response. Sometimes, though, too many cytokines get released. This is known as a cytokine storm, and it makes the body attack itself, resulting in potentially deadly damage to healthy tissue.

Etymology

Origin of cytokine

First recorded in 1970–75; cyto- ( def. ) + -kine, from Greek kineîn “to move, set in motion”; cf. -kinin ( def. )

Example Sentences

See Examples For:

cytokine

But in some cases of severe infection, the immune system can overcorrect and send out an excess amount of these proteins, a serious and potentially fatal reaction called a cytokine storm.

From Los Angeles Times ● Jun. 15, 2026

That fatty molecule belongs to a group called cardiolipins, which are known to stimulate cytokine release.

From Science Daily ● Apr. 25, 2026

This leads to stronger internal signaling, which increases T-cell activation, boosts cytokine production, and improves the cells' ability to kill tumors.

From Science Daily ● Apr. 10, 2026

"In addition, LC-Mo correlated with the severity of fatigue and respiratory symptoms and was associated with elevated cytokine levels in blood plasma, which are an indicator of inflammatory processes in the body."

From Science Daily ● Mar. 26, 2026

Their model accurately reproduced the biological signs of immune-related liver injury, including T cell activation, cytokine release, and liver cell damage, closely mirroring what happens in susceptible people.

From Science Daily ● Oct. 15, 2025