cytokine
noun
cy·to·kine
ˈsī-tə-ˌkīn 
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.
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.
Chiea C. Khor et al.Examples of cytokine in a Sentence
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The delivery of cytokines can stimulate the white blood cell production that is damaged by exposure; treatment with potassium iodide or Prussian blue can help eliminate radioactive particles from the body; and proper washing can prevent skin burns that might take days to show up.
—New Atlas, 28 Jan. 2026
More cytokines are not always better.
—Julie Scott, Verywell Health, 26 Jan. 2026
The interferons then trigger a cascade of other chemicals to be produced including cytokines.
—Bruce Y. Lee, Forbes.com, 24 Jan. 2026
Both the mice and human cell clusters showed damage to cardiac tissue and function—but applying drugs that block cytokines partially restored that function.
—Lauren J. Young, Scientific American, 10 Dec. 2025
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New Atlas, 28 Jan. 2026
More cytokines are not always better.
—Julie Scott, Verywell Health, 26 Jan. 2026
The interferons then trigger a cascade of other chemicals to be produced including cytokines.
—Bruce Y. Lee, Forbes.com, 24 Jan. 2026
Both the mice and human cell clusters showed damage to cardiac tissue and function—but applying drugs that block cytokines partially restored that function.
—Lauren J. Young, Scientific American, 10 Dec. 2025
See All Example Sentences for cytokine
Cite this Entry
“Cytokine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cytokine. Accessed 31 Jan. 2026.
Copy CitationMedical Definition
cytokine
noun
cy·to·kine
ˈsīt-ə-ˌkīn
: 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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