The term RNA interference (RNAi) describes the use of double-stranded RNA t
o target specific mRNAs for degradation, thereby silencing their expression
. RNAi is one manifestation of a broad class of RNA silencing phenomena tha
t are found in plants, animals and fungi. The discovery of RNAi has changed
our understanding of how cells guard their genomes, led to the development
of new strategies for blocking gene function, and may yet yield RNA-based
drugs to treat human disease.