The nuclei of cells are full of noncoding RNAs, meaning RNAs that will not make proteins, however their functions is sometimes not really clear. In the last few years more and more roles have been attributed to this “junk” and it is now clear that they are important in health and disease. In all of this, what are piRNAs? What is their link to fertility? What is the perspective of RNA-based technologies? Prof Pei-Hsuan Wu gives us some interesting insights, interviewed by Olimpia Bompadre and presented by Rouaa Ben Chaabene.