Editing Human genome (section)

=== Non-coding genes ===
{{Main|Non-coding RNA|Non-coding DNA}}

Noncoding RNA molecules play many essential roles in cells, especially in the many reactions of [[Translation (biology)|protein synthesis]] and [[Post-transcriptional modification|RNA processing]]. Noncoding genes include those for [[tRNA]]s, [[Ribosome|ribosomal]] RNAs, [[microRNA]]s, [[snRNA]]s and [[lncRNA|long non-coding RNA]]s (lncRNAs).<ref name="ENCODEScience">{{cite journal | vauthors = Pennisi E | title = Genomics. ENCODE project writes eulogy for junk DNA | journal = Science | volume = 337 | issue = 6099 | pages = 1159–1161 | date = Sep 2012 | pmid = 22955811 | doi = 10.1126/science.337.6099.1159 }}</ref><ref>{{cite journal | vauthors = Iyer MK, Niknafs YS, Malik R, Singhal U, Sahu A, Hosono Y, Barrette TR, Prensner JR, Evans JR, Zhao S, Poliakov A, Cao X, Dhanasekaran SM, Wu YM, Robinson DR, Beer DG, Feng FY, Iyer HK, Chinnaiyan AM | title = The landscape of long noncoding RNAs in the human transcriptome | journal = Nature Genetics | volume = 47 | issue = 3 | pages = 199–208 | date = Mar 2015 | pmid = 25599403 | doi = 10.1038/ng.3192 | pmc=4417758}}</ref><ref>{{cite journal | vauthors = Eddy SR | title = Non-coding RNA genes and the modern RNA world | journal = Nature Reviews Genetics | volume = 2 | issue = 12 | pages = 919–929 | date = Dec 2001 | pmid = 11733745 | doi = 10.1038/35103511 | s2cid = 18347629 }}</ref><ref name="MarkelManagadze2013">{{cite journal | vauthors = Managadze D, Lobkovsky AE, Wolf YI, Shabalina SA, Rogozin IB, Koonin EV | title = The vast, conserved mammalian lincRNome | journal = PLOS Computational Biology | volume = 9 | issue = 2 | pages = e1002917 | year = 2013 | pmid = 23468607 | doi = 10.1371/journal.pcbi.1002917 | pmc=3585383| bibcode = 2013PLSCB...9E2917M | doi-access = free }}</ref> The number of reported non-coding genes continues to rise slowly but the exact number in the human genome is yet to be determined. Many RNAs are thought to be non-functional.<ref name="PalazzoLee2015">{{cite journal | vauthors = Palazzo AF, Lee ES | title = Non-coding RNA: what is functional and what is junk? | journal = Frontiers in Genetics | volume = 6 | pages = 2 | year = 2015 | pmid = 25674102 | doi = 10.3389/fgene.2015.00002 | pmc=4306305| doi-access = free }}</ref>

Many ncRNAs are critical elements in gene regulation and expression. Noncoding RNA also contributes to epigenetics, transcription, RNA splicing, and the translational machinery. The role of RNA in genetic regulation and disease offers a new potential level of unexplored genomic complexity.<ref>{{cite journal | vauthors = Mattick JS, Makunin IV | title = Non-coding RNA | journal = Human Molecular Genetics | volume = 15 | issue = Spec No 1 | pages = R17–29 | date = Apr 2006 | pmid = 16651366 | doi = 10.1093/hmg/ddl046 | doi-access = free }}</ref>