Nucleic acids are not only essential genetic elements or being potential therapeutic and research tools, but sensing their molecular signatures is also an important quality control mechanism have evolved to maintain the integrity of human genome. The recent discovery of pattern recognition receptors (PRRs) and the extensive studies in this field have revealed that certain innate sensors recognize RNAs released from infectious agents or even from human cells to modulate specific signalling pathways. In this book, we highlight our current understanding of RNA sensing by innate receptors and discuss the regulatory mechanisms that normally prevent inappropriate cellular responses. The book features expanded coverage of the latest advances relevant to recognition of RNA by the PKR and the importance of JAK/STAT signaling in these processes. To resolve some issues related to RNA signaling, the book integrates very well formulated hypotheses with a range of basic and new powerful techniques.