Only eight years after their 1998 paper in Nature announced the discovery of RNA interference (RNAi), in which double-stranded RNA is used to silence genes, Andrew Fire and Craig Mello awoke in the wee hours of the morning of October 2 to the news that they were the 2006 recipients of the Nobel Prize in Physi­ology or Medicine. Such a short time between discovery and prize often signifies a finding's importance: it took only nine years for Watson and Crick to win the Nobel for discovering the structure of DNA. The Nobel Assembly's confidence in the importance of RNAi is obvious.

The initial experiment by Fire and Mello, showing that double-stranded RNA injected into worms would silence the gene with the corresponding sequence, was a clarion call to labs around the world, announcing a new method for investigating gene functions. After the initial discovery, other labs showed that small ­double-­stranded RNAs could be used to selectively silence genes in human cells, providing a much-sought-after general approach to exploring the functions of all 21,000 human genes.