Location of long noncoding RNAs in the genome and roles of long noncoding RNAs in regulation of cellular processes. (A) Long noncoding RNA (lncRNA) genes reside in various genomic locations, such as in the promoters, enhancers, introns, or anti-sense coding regions of genes, and can also be in their own stand-alone position in the genome. These lncRNA genes sometimes contain small RNA genes, like microRNA (miRNA), that are spliced out of the lncRNA after transcription. (B) The actions of lncRNAs affect many cellular processes. lncRNAs may serve as scaffolds to bring nuclear receptors in contact with promoters of their target genes via chromatin looping, or they may recruit an epigenetic modifier to the chromatin. They can also bind proteins, such as transcription factors, to prevent their binding to DNA – similar to their mechanism of miRNA inhibition. Among the effects lncRNAs have on mRNA, translational activation and maintenance of mRNA stability are also important.