Review Volume 12, Issue 21 pp 22335—22349

Figure 2. Classification of lncRNAs based on their genomic region. I, II: Sense lncRNAs and antisense lncRNAs are located on the same and opposite strands, respectively, and overlap with neighboring genes; III: intronic lncRNAs are transcribed entirely from the introns of protein-encoding genes; IV: intergenic lncRNAs lie within the genomic interval between two genes; V, VI: divergent/convergent lncRNAs are transcribed in the opposite/same direction as nearby protein-encoding genes; VII, VIII: promoter/enhancer-associated lncRNAs originate from the promoter/enhancer regions of protein-encoding genes; and IX: lncRNAs are situated upstream of the promoter.