Keratin 18 Keratin 18 Keratin 18 is a type I cytokeratin. It is, together with its filament partner keratin 8, perhaps the most commonly found products of the intermediate filament gene family. They are expressed in single layer epithelial tissues of the body. Mutations in this gene have been linked to cryptogenic cirrhosis. Two transcript variants encoding the same protein have been found for this gene. Keratin 18 is often used together with keratin 8 and keratin 19 to differentiate cells of epithelial origin from hematopoietic cells in tests that enumerate circulating tumor cells in blood. Keratin 18 has been shown to
Lectin their particular high specificity for foreign glycoconjugates (e.g. those of fungi, invertebrates, and animals) and used in biomedicine for blood cell testing and in biochemistry for fractionation. Although they were first discovered more than 100 years ago in plants, now lectins are known to be present throughout nature. It is generally believed that the earliest description of a lectin was given by Peter Hermann Stillmark in his doctoral thesis presented in 1888 to the University of Dorpat. Stillmark isolated ricin, an extremely toxic hemagglutinin, from seeds of the castor plant ("Ricinus communis"). The first lectin to be purified on a