Keratin 7

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Keratin 7
Symbols KRT7 ; CK7; K2C7; K7; SCL
External IDs OMIM148059 MGI96704 HomoloGene4058 GeneCards: KRT7 Gene
RNA expression pattern
PBB GE KRT7 209016 s at tn.png
More reference expression data
Species Human Mouse
Entrez 3855 110310
Ensembl ENSG00000135480 ENSMUSG00000023039
UniProt P08729 Q9DCV7
RefSeq (mRNA) NM_005556 NM_033073
RefSeq (protein) NP_005547 NP_149064
Location (UCSC) Chr 12:
52.63 – 52.65 Mb
Chr 15:
101.41 – 101.43 Mb
PubMed search [1] [2]

Keratin, type II cytoskeletal 7 also known as cytokeratin-7 (CK-7) or keratin-7 (K7) or sarcolectin (SCL) is a protein that in humans is encoded by the KRT7 gene.[1][2][3] Keratin 7 is a type II keratin. It is specifically expressed in the simple epithelia lining the cavities of the internal organs and in the gland ducts and blood vessels.


Keratin-7 is a member of the keratin gene family. The type II cytokeratins consist of basic or neutral proteins which are arranged in pairs of heterotypic keratin chains coexpressed during differentiation of simple and stratified epithelial tissues. This type II cytokeratin is specifically expressed in the simple epithelia lining the cavities of the internal organs and in the gland ducts and blood vessels. The genes encoding the type II cytokeratins are clustered in a region of chromosome 12q12-q13. Alternative splicing may result in several transcript variants; however, not all variants have been fully described.[3]

Keratin-7 is found in simple glandular epithelia, and in transitional epithelium. Epithelial cells of the lung and breast both contain keratin-7, but some other glandular epithelia, such as those of the colon and prostate, do not. Because the keratin-7 antigen is found in both healthy and neoplastic cells, antibodies to CK7 can be used in immunohistochemistry to distinguish ovarian and transitional cell carcinomas from colonic and prostate cancers, respectively. It is commonly used together with CK20 when making such diagnoses.[4]


  1. ^ Rosenberg M, Fuchs E, Le Beau MM, Eddy RL, Shows TB (Aug 1991). "Three epidermal and one simple epithelial type II keratin genes map to human chromosome 12". Cytogenet Cell Genet 57 (1): 33–8. doi:10.1159/000133109. PMID 1713141. 
  2. ^ Schweizer J, Bowden PE, Coulombe PA, Langbein L, Lane EB, Magin TM, Maltais L, Omary MB, Parry DA, Rogers MA, Wright MW (Jul 2006). "New consensus nomenclature for mammalian keratins". J Cell Biol 174 (2): 169–74. doi:10.1083/jcb.200603161. PMC 2064177. PMID 16831889. 
  3. ^ a b "Entrez Gene: KRT7 keratin 7". 
  4. ^ Leong, Anthony S-Y; Cooper, Kumarason; Leong, F Joel W-M (2003). Manual of Diagnostic Cytology (2 ed.). Greenwich Medical Media, Ltd. p. 173. ISBN 1-84110-100-1. 

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