Today, scientists are using the RNAi mechanism to learn more about what particular genes do and how to alter their function. Determining gene function is a relatively simple matter of inserting double-stranded RNA molecules that have a particular sequence into cells and observing the effects after RNAi silences the corresponding gene.

Conceivably, this method may one day be used to silence gene mutations that cause human diseases such as Huntington's disease, rheumatoid arthritis, cancer, and many others. By using either the body's own mutations or viral invaders, scientists may develop a new type of drug—for example, one that switches off the genes of a cancer cell and leaves healthy cells unaffected. However, because RNAi's potential effects are so powerful, scientists must first determine that they can control the mechanism so that only the target gene is silenced, and not others.