{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Prealbumin or transthyretin (TTR) is a non-glycosylated homotetrameric carrier protein that binds and transports triiodothyronine (T3), thyroxine (T4), and retinol-binding protein (RBP). Transthyretin is mostly synthesized in the liver, but is also synthesized in pancreatic islet cells, retina, and epithelial cells of choroid plexus. The liver secretes TTR into the blood, and the choroid plexus secretes TTR into the cerebrospinal fluid. TTR mutations are associated with familial amyloidosis polyneuropathy (FAP), familial amyloidosis cardiomyopathy (FAC), and senile systemic amyloidosis (SSA). TTR amyloidosis is caused by aggregation of monomers which misfold after they dissociate from the homotetramer. TTR can also influence a wide spectrum of endothelial cell functions to control tumor and immune cell migration and infiltration and play an essential role in the tumor microenvironment."}]}]}