The role of RNA in regulating gene expression has become a topic of intense interest. In this book, internationally recognized experts in RNA research explore and discuss the methods whereby RNA can regulate gene expression with examples in yeast, Drosophila, mammals, and viral infection, as well as highlight the application of this knowledge in therapeutics and research. Topics include: gene silencing and gene activation, the hammerhead ribozyme, epigenetic regulation, RNAi, microRNA, and pyknons. This comprehensive publication is intended for readers with teaching or research interests in RNA, the regulation of gene expression, genetics, genomics, and molecular biology.