Figure 1

Genomic position of lncRNAs may offer clues to their function. The positional relationship of the lncRNAs (thin arrows) compared to the transcript they regulate (thick arrow) is shown. Serrated lines indicate the long distance between the intergenic lncRNAs and the nearest known transcript, which they may or may not regulate. The three major functional mechanisms employed by currently characterized lncRNAs are listed to the right, and the likelihood that each strategy is used is shown by: - (unlikely to be used), + (likely to be used) or ++ (very likely to be used) signs.