TTR was originally called prealbumin because it ran faster than albumins on electrophoresis gels.Prealbumin is produced by the choroid plexus, by pancreatic islet cells in the embryonic yolk sac, and by enterochromaffin cells in the gastrointestinal mucosa, but the liver is quantitatively the most important source.9 Liver production is maintained until late in liver disease. Hydration status does not affect prealbumin levels. A negative acute phase reactant, the prealbumin level will transiently decrease in the presence of inflammation and in the immediate postsurgical period. Serum levels also decline in patients with conditions associated with protein malnutrition, such as malignancy, cirrhosis, protein-losing enteropathy, and zinc deficiency.