Editing Esophagus (section)

==Gene and protein expression==
About 20,000 protein-coding genes are expressed in human cells and nearly 70% of these genes are expressed in the normal esophagus.<ref>{{Cite web|url=https://www.proteinatlas.org/humanproteome/esophagus|title=The human proteome in esophagus - The Human Protein Atlas|website=www.proteinatlas.org|access-date=2017-09-22}}</ref><ref>{{Cite journal|last1=Uhlén|first1=Mathias|last2=Fagerberg|first2=Linn|last3=Hallström|first3=Björn M.|last4=Lindskog|first4=Cecilia|last5=Oksvold|first5=Per|last6=Mardinoglu|first6=Adil|last7=Sivertsson|first7=Åsa|last8=Kampf|first8=Caroline|last9=Sjöstedt|first9=Evelina|date=2015-01-23|title=Tissue-based map of the human proteome|journal=Science|language=en|volume=347|issue=6220|pages=1260419|doi=10.1126/science.1260419|issn=0036-8075|pmid=25613900|s2cid=802377}}</ref> Some 250 of these genes are more specifically expressed in the esophagus with less than 50 genes being highly specific. The corresponding esophagus-specific proteins are mainly involved in squamous differentiation such as [[keratin]]s [[Keratin 13|KRT13]], [[Keratin 4|KRT4]] and [[Keratin 6C|KRT6C]]. Other specific proteins that help lubricate the inner surface of esophagus are [[mucin]]s such as [[Mucin 21, cell surface associated|MUC21]] and MUC22. Many genes with elevated expression are also shared with skin and other organs that are composed of [[Epithelium|squamous epithelia]].<ref>{{Cite journal|last1=Edqvist|first1=Per-Henrik D.|last2=Fagerberg|first2=Linn|last3=Hallström|first3=Björn M.|last4=Danielsson|first4=Angelika|last5=Edlund|first5=Karolina|last6=Uhlén|first6=Mathias|last7=Pontén|first7=Fredrik|date=2014-11-19|title=Expression of Human Skin-Specific Genes Defined by Transcriptomics and Antibody-Based Profiling|journal=Journal of Histochemistry & Cytochemistry|language=en|volume=63|issue=2|pages=129–141|doi=10.1369/0022155414562646|pmid=25411189|pmc=4305515}}</ref>