Regulatory non-coding RNAs: everything is possible, but what is important?

In recent years, the number of annotated noncoding RNAs (ncRNAs) and RNA-binding proteins (RBPs) has increased dramatically. The wide range of RBPs identified highlights the enormous potential for RNA in virtually all aspects of cell biology, from transcriptional regulation to metabolic control. Yet, there is a growing gap between what is possible and what has been demonstrated to be functionally important. Here we highlight recent methodological developments in the study of RNA–protein interactions, discuss the challenges and opportunities for exploring their functional roles, and provide our perspectives on what is needed to bridge the gap in this rapidly expanding field.