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
Recent Examples on the Web
Different genes for different cytokines, growth factors or other proteins could be swapped in to target specific diseases of the ocular surface, potentially extending the approach beyond corneal wounds to chronic inflammatory conditions.
—
Samantha Agate,
Charlotte Observer,
16 June 2026
One of the body’s natural defense mechanisms against a virus like COVID or influenza is the release of cytokines, proteins that act as chemical messengers helping to coordinate the immune system’s response.
—
Los Angeles Times,
15 June 2026
The body naturally relies on small chemical messengers called cytokines to control inflammation and healing.
—
Khloe Quill,
FOXNews.com,
5 June 2026
The virus appears to trigger a destructive host response in which infected endothelium, immune activation, platelets, coagulation, cytokine signaling, and complement converge to destabilize the vascular barrier.
—
Steve Brozak,
Forbes.com,
15 May 2026
See All Example Sentences for cytokine
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Samantha Agate,
Charlotte Observer,
16 June 2026
One of the body’s natural defense mechanisms against a virus like COVID or influenza is the release of cytokines, proteins that act as chemical messengers helping to coordinate the immune system’s response.
—
Los Angeles Times,
15 June 2026
The body naturally relies on small chemical messengers called cytokines to control inflammation and healing.
—
Khloe Quill,
FOXNews.com,
5 June 2026
The virus appears to trigger a destructive host response in which infected endothelium, immune activation, platelets, coagulation, cytokine signaling, and complement converge to destabilize the vascular barrier.
—
Steve Brozak,
Forbes.com,
15 May 2026
See All Example Sentences for cytokine
Cite this Entry
“Cytokine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cytokine. Accessed 4 Jul. 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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