Role of cytokeratins in early embryogenesis in Xenopus and mouse, regeneration of liver and keratinization of epithelial cells in adult animals have been worked out by manipulating RNA expression as well as protein synthesis using chemical modulators, antibodies, antisense DNAs or by transgenic expression. Irrespective of the various responses of cells/tissue to the altered keratin network system, keratins help in providing architecture and a definite cellular organisation to the tissue as a whole, by controlling morphogenetic migration of cells. The role of cytokeratins in the morphogenetic movements provides mechanical integrity and endurance to the cells.