Linda A. Cicero / Stanford News Service · CC BY 3.0

A Stanford biologist who, with Craig Mello, discovered RNA interference — a mechanism by which cells use double-stranded RNA to silence specific genes. Published in 1998 from work done at the Carnegie Institution, the finding gave researchers a precise tool for switching individual genes off to study what they do, and later became the basis for an entire class of RNAi-based drugs. Fire and Mello shared the 2006 Nobel Prize in Physiology or Medicine for the discovery.