Two better-known alternatives, antisense and RNA-interference, the latter of which is being used now by Monsanto, can silence or shut down genes but cannot turn them on or make them louder.

FORBES: Magazine Article

What's more, later research would reveal that genes that create this kind of RNA--known as RNAi, for RNA interference--existed in plants, fruit flies and even people.

FORBES: Biotech Breakthrough Wins Nobel Prize

Sirna has been in the news of late because Andrew Fire and Craig Mello, the discoverers of the technology upon which Sirna's drugs are based--RNA interference, or RNAi-- won a Nobel Prize for medicine last month.

FORBES: Inside Merck's Biotech Buy

Insert Therapeutics and Intradigm are also working on targeted treatments, but both companies are also exploring the use of a Nobel Prize-winning therapy based on RNA interference (RNAi).

FORBES: Nanotech Puts Cancer In The Cross Hairs

One way in which this occurs is through "RNA interference", which involves the introduction of double-stranded RNA molecules.

BBC: NEWS | Science/Nature | Salvage prospect for 'junk' DNA