Editing Small intestine (section)

=== Gene and protein expression ===
About 20,000 protein coding genes are [[Gene expression|expressed]] in human cells and 70% of these genes are expressed in the normal duodenum.<ref>{{Cite web|url=https://www.proteinatlas.org/humanproteome/small+intestine|title=The human proteome in small intestine - The Human Protein Atlas|website=www.proteinatlas.org|access-date=2017-09-26}}</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|s2cid=802377|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}}</ref> Some 300 of these genes are more specifically expressed in the duodenum with very few genes expressed only in the small intestine. The corresponding specific proteins are expressed in glandular cells of the mucosa, such as [[Fatty acid-binding protein|fatty acid binding protein]] [[FABP6]].  Most of the more specifically expressed genes in the small intestine are also expressed in the duodenum, for example [[FABP2]] and the [[DEFA6]] protein expressed in secretory granules of [[Paneth cell]]s.<ref>{{Cite journal|last1=Gremel|first1=Gabriela|last2=Wanders|first2=Alkwin|last3=Cedernaes|first3=Jonathan|last4=Fagerberg|first4=Linn|last5=Hallström|first5=Björn|last6=Edlund|first6=Karolina|last7=Sjöstedt|first7=Evelina|last8=Uhlén|first8=Mathias|last9=Pontén|first9=Fredrik|s2cid=21302849|date=2015-01-01|title=The human gastrointestinal tract-specific transcriptome and proteome as defined by RNA sequencing and antibody-based profiling|journal=Journal of Gastroenterology|language=en|volume=50|issue=1|pages=46–57|doi=10.1007/s00535-014-0958-7|pmid=24789573|issn=0944-1174}}</ref>