Glycoprotein synthesis is a central function of the endoplasmic reticulum and dolichol phosphates play an important role in the establishment of the core part of the oligosaccharide chain. Dolichol metabolism requires the cooperative action of several intracellular organelles and disturbance in the metabolism is one of the factors behind changes in glycosylation reactions during chemical carcinogenesis. The glycoproteins synthesized in the endoplasmic membranes also appear to enter to the cytoplasm for further transport to various intracellular membranes.