transcription factor

noun

: any of various proteins that bind to DNA and play a role in the regulation of gene expression by promoting transcription

Examples of transcription factor in a Sentence

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Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
In bacteria, transcription factors are rather like keys that fit the locks of unique binding sites on DNA. — Philip Ball, Quanta Magazine, 18 June 2026 For this research, each transcription factor was tested individually in aged fibroblasts. — William A. Haseltine, Forbes.com, 1 Apr. 2026 The team evolved a transcription factor—a protein that activates the expression of a gene target—with mutations only beneficial in mammalian cells, not bacteria. — IEEE Spectrum, 27 July 2025 But with toxic levels of cobalt, the transcription factor is active without low oxygen levels, leading to abnormally high amounts of hemoglobin-carrying red blood cells—explaining the woman’s high hemoglobin levels. — Beth Mole, ArsTechnica, 2 July 2026 See All Example Sentences for transcription factor

Word History

First Known Use

1969, in the meaning defined above

Time Traveler
The first known use of transcription factor was in 1969

Rhymes for transcription factor

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Browse Nearby Words

transcriptional
transcription factor
transcriptionist
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Cite this Entry

“Transcription factor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/transcription%20factor. Accessed 7 Jul. 2026.

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Medical Definition

transcription factor

noun
: any of various proteins that bind to DNA and play a role in the regulation of gene expression by promoting transcription

More from Merriam-Webster on transcription factor

Britannica.com: Encyclopedia article about transcription factor

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