In PNAS this week, researchers at the Centre National de la Recherche Scientifique have found that piRNAs play a role in post-transcriptional gene-silencing of transposable elements in Drosophila egg cells. They showed that the repression of the functional I elements located in euchromatin requires piRNA proteins, and the amount of ovarian I element piRNAs correlates with the strength of the repression.