Role of lncRNAs in health and disease-size and shape matter.

Most of the mammalian genome including a large fraction of the non-protein coding transcripts has been shown to be transcribed. Studies related to these non-coding RNA molecules have predominantly focused on smaller molecules like microRNAs. In contrast, long non-coding RNAs (lncRNAs) have long been considered to be transcriptional noise. Accumulating evidence suggests that lncRNAs are involved in key cellular and developmental processes. Several critical questions regarding functions and properties of lncRNAs and their circular forms remain to be answered. Increasing evidence from high-throughput sequencing screens also suggests the involvement of lncRNAs in diseases such as cancer, although the underlying mechanisms still need to be elucidated. Here, we discuss the current state of research in the field of lncRNAs, questions that need to be addressed in light of recent genome-wide studies documenting the landscape of lncRNAs, their functional roles and involvement in diseases. We posit that with the availability of high-throughput data sets it is not only possible to improve methods for predicting lncRNAs but will also facilitate our ability to elucidate their functions and phenotypes by using integrative approaches.