Cytokeratins are proteins, containing keratin, constructed of intermediate filaments, found in the cytoskeleton structures of epithelial and trichocytic cells. In form there are two types, basic (Type 1) and neutral (Type 2).
In cell cytoplasm, the intermediate filaments form a network of a fibrous nature between the nucleus and the cell membrane, thus cytokeratins role are seen as important structural support activities. Additionally they are important meditating structures in cell movement and differentiation.