Argonaute Journeys into the Heart of RISC

Abstract
Identifying the "slicer" component of the RNA-induced silencing complex (RISC) complex has been a major goal of those interested in the RNA interference pathway of gene silencing. In their Perspective, Sontheimer and Carthew discuss a pair of recent studies ( Liu et al., Song et al.) that identify the protein Argonaute2 as the slicer element of RISC that cleaves target messenger RNAs.