cy·​to·​kine ˈsī-tə-ˌkīn How to pronounce cytokine (audio)
plural cytokines
: any of a class of immunoregulatory proteins (such as interleukin or interferon) that are secreted by cells especially of the immune system
Most cytokines are produced primarily in the presence of disease or immunization and contribute to immune responses, inflammation, and endothelial cell activation; others are involved in tissue repair.Charles A. Dinarello et al.
The proinflammatory cytokine interleukin-2 determines the magnitude and duration of the T-cell response immediately after antigen encounter and assists in the maturation of macrophages and the proliferation of B cells and natural killer cells …Chiea C. Khor et al.

Examples of cytokine in a Sentence

Recent Examples on the Web Furthermore, studies have shown that CBD inhibits the release of pro-inflammatory cytokines, molecules responsible for promoting inflammation. Amber Smith, Discover Magazine, 15 Aug. 2023 For example, Cole and his colleagues found that the white blood cells of lonely people tend to turn on genes involved in making pro-inflammatory cytokines and turn off genes responsible for keeping cell proliferation in check. Connie Chang, Popular Mechanics, 13 June 2023 Made by cows during the first few days after giving birth, colostrum is rich in immune-boosting components like antibodies, growth factors, and cytokines. Amber Smith, Discover Magazine, 25 Apr. 2023 Chronic lack of sleep causes the body to make more proteins in cells called cytokines. Nick Blackmer, Verywell Health, 25 May 2023 The systematic review also looked at the role low-dose naltrexone can play in decreasing pro-inflammatory cytokine levels. Stephanie Brown, Verywell Health, 7 June 2023 An analysis of blood samples from nine of these patients — all of whom had gotten Pfizer — found elevated cytokine levels. Berkeley Lovelace Jr., NBC News, 5 May 2023 In this study, Golden et al. demonstrated both in cell culture and in mice that mitochondrial antiviral signaling protein (MAVS) activation along with cytokine production contribute to the pathogenesis of Crimean-Congo Hemorrhagic Fever Virus, identifying key new targets for potential treatments. William A. Haseltine, Forbes, 3 June 2022 By reducing the production of these cytokines, CBD may help alleviate inflammation. Amber Smith, Discover Magazine, 12 June 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'cytokine.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


cyt- + -kine (as in lymphokine)

First Known Use

1974, in the meaning defined above

Time Traveler
The first known use of cytokine was in 1974

Dictionary Entries Near cytokine

Cite this Entry

“Cytokine.” Dictionary, Merriam-Webster, Accessed 25 Sep. 2023.

Medical Definition


cy·​to·​kine ˈsīt-ə-ˌkīn How to pronounce cytokine (audio)
: any of a class of immunoregulatory proteins (as interleukin, tumor necrosis factor, and interferon) that are secreted by cells especially of the immune system

More from Merriam-Webster on cytokine

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