cytokine

noun

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
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Physical damage to the skin releases inflammatory cytokines—proteins that control inflammation and trigger an immune response.5 Scratching the affected areas can make the areas larger. Mark Gurarie, Health, 22 June 2025 These nerves control the release of cytokines, which are proteins released by immune cells to trigger inflammation. Sangeeta S. Chavan, IEEE Spectrum, 9 June 2025 Two cytokines were measured: interleukin 1-β (IL-1β) and interleukin 2-R (IL-2R). New Atlas, 12 Apr. 2025 This feature, essentially a failsafe, Young explained, allows CAR cells to take a break, which can be useful in terms of keeping cytokine production from getting out of control and from becoming exhausted from working too long without time to rejuvenate. Paul Sisson, San Diego Union-Tribune, 6 July 2025 See All Example Sentences for cytokine

Word History

Etymology

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

Cite this Entry

“Cytokine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cytokine. Accessed 22 Jul. 2025.

Medical Definition

cytokine

noun
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

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