Cytokeratin 19 is part of a subfamily of intermediate filament proteins and are characterized by a remarkable biochemical diversity, represented in human epithelial tissues by at least 20 different polypeptides. Cytokeratins range in molecular weight from 40-68 kDa and isoelectric pH between 4.9 - 7.8. The individual human cytokeratins are numbered 1 to 20. The various epithelia in the human body usually express cytokeratins which are not only characteristic of the type of epithelium, but also related to the degree of maturation or differentiation within an epithelium. Cytokeratin subtype expression patterns are used to an increasing extent in the distinction of different types of epithelial malignancies. The cytokeratin antibodies are not only of assistance in the differential diagnosis of tumors using immunohistochemistry on tissue sections, but are also a useful tool in cytopathology and flow cytometric assays. For example, cytokeratin 19 is not expressed in hepatocytes, therefore, it is useful in the identification of liver metastasis.
Protein Aliases: 40-kDa keratin intermediate filament; C K1CS; CK 19; CK-19; cytokeratin 19; Cytokeratin-19; K19; keratin 19, type I; Keratin, type I cytoskeletal 19; keratin, type I, 40-kd; Keratin-19; MGC15366
Gene Aliases: CK19; K19; K1CS; KRT19
UniProt ID: (Human) P08727
Entrez Gene ID: (Human) 3880