miRNA

noun \ ˌem-ˌī-ˌär-(ˌ)en-ˈā \

Definition of miRNA

genetics

: microrna

A major part of this regulation is performed by microRNAs (miRNAs), small RNA molecules encoded by the genome that are not translated into proteins; rather, they control the expression of genes.
—Sebastien S. Hebert et al.

First Known Use of mirna

2001

in the meaning defined above

See Words from the same year

NEW! Time Traveler

Medical Dictionary

miRNA

noun \ ˌem-ˌī-ˌär-ˌen-ˈā \

medical Definition of miRNA

: microrna

MicroRNAs (miRNAs) are 20- to 22-nucleotide RNAs that regulate the function of eukaryotic messenger RNAs (mRNAs) and play important roles in development, cancer, stress responses, and viral infections.
—J. Ross Buchan et al., Science, 21 Dec. 2007

Many of the noncoding RNAs, epitomized by the miRNA, have regulatory functions in normal cells. The aberrant expression of miRNA promotes tumorigenesis, metastasis, and other features of cancer.
—Frank J. Slack et al., The New England Journal of Medicine, 18 Dec. 2008

Seen and Heard

What made you want to look up miRNA? Please tell us where you read or heard it (including the quote, if possible).

show

WORD OF THE DAY

notorious

play

widely and unfavorably known

BROWSE DICTIONARY

mirligoes

mirliton

miRNA

Miró

Mirounga

Test Your Vocabulary

Words for Summer: A Quiz

Which of the following words means “of or relating to summer”?

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ

SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Words at Play

Ask the Editors

Word Games