More than 99% of the circulating T4 and T3 are boundto plasmaproteins (e.g., thyroxine-binding globulin, transthyretin, and albumin). The measurements of total T4 and T3 can be influencedby the factors that alter the protein binding, such as pregnancy,liver disease, nephrotic syndrome, and the use of certain medications(like oral contraceptives or steroids), leading to misleading results. Although the total T4 and T3 levels change withthe variation in thyroxine-binding globulin, the free serum levelsof these hormones remain constant. The gene discussed is SERPINA7; the disease is liver disorder.