RESEARCH Localization and abundan lncRNAs at single-cell and

of long non-coding RNAs (lncRNAs) expressed from fosters hypotheses for potential molecular roles. Unlike Cabili et al. Genome Biology (2015) 16:20 DOI 10.1186/s13059-015-0586-4in three dimensions) [6-8]. Sequencing studies cannotPhiladelphia, PA 19104, USAFull list of author information is available at the end of the articlemammalian genomes. While a number of studies have implicated functional roles lncRNAs [1-3] the vast ma-jority remain uncharacterized [4,5]. Even very basic properties such as subcellular localization or absolute abundance in single cells remain unknown. mRNAs, which produce proteins, lncRNA themselves must localize to their particular site of action, making their location within the cell important. For instance, ex-clusively nuclear localization would argue against puta-tive lncRNAs encoding short peptide sequences, because translation occurs in the cytoplasm. Further, localization to particular areas within the nucleus may suggest differ-ent functionalities- for instance, finding a lncRNA pri-marily in the nucleus near its site of transcription may suggest that it regulates transcription of a proximal gene (that is, regulation in cis or regulation of proximal loc