1.1 LncRNA
LncRNAs, longer than 200 nt, stimulate or inhibit transcription at the transcriptional level, influence mRNA splicing, editing, translation, or stability at the post-transcriptional level, and performing epigenetic regulation[2]. As reside in various cells and subcellular localizations, different lncRNAs serve diverse activities at different times. The following categories can be determined by where they are located on coding genes: 1) Intergenic (has no overlap with protein-coding genes); 2) Antisense (enriched around the promoter or terminator ends of the sense transcript); 3) Intronic (located in the area of gene coding sites); 4) Divergent lncRNA (abundanted in the vicinity of transcription start sites); 5) Pseudogenes (genes that have no potential of coding) [4]. Divergent lncRNAs, which are head-to-head overlap with the coding genes, account for about 20% of all lncRNAs. Divergent lncRNAs are strongly tied to essential growth and developmental regulatory genes. Their functions are associated with those of their neighboring coding genes, which can regulate those genes in cis and encourage the diversification of higher eukaryotic phenotypes[5]. With a countless number of lncRNA, more are continually being found and labeled, and many lncRNAs’ roles have not yet been thoroughly investigated.