Cytokeratin

Keratin intermediate filaments in epithelial cells (red stain).

Cytokeratins are keratin proteins found in the intracytoplasmic cytoskeleton of epithelial tissue. They are an important component of intermediate filaments, which help cells resist mechanical stress.^[1] Expression of these cytokeratins within epithelial cells is largely specific to particular organs or tissues. Thus they are used clinically to identify the cell of origin of various human tumors.

^ Herrmann H, Bär H, Kreplak L, Strelkov SV, Aebi U (July 2007). "Intermediate filaments: from cell architecture to nanomechanics". Nat. Rev. Mol. Cell Biol. 8 (7): 562–73. doi:10.1038/nrm2197. PMID 17551517. S2CID 27115011.

[pmid17551517-1] Herrmann H, Bär H, Kreplak L, Strelkov SV, Aebi U (July 2007). "Intermediate filaments: from cell architecture to nanomechanics". Nat. Rev. Mol. Cell Biol. 8 (7): 562–73. doi:10.1038/nrm2197. PMID 17551517. S2CID 27115011.

[1]