SERPINA7 (Thyroxine-binding globulin, TBG): SERPINA7 is a carrier protein primarily produced in the liver that circulates in the bloodstream. It binds and transports thyroid hormones — mainly thyroxine (T4) and triiodothyronine (T3) — ensuring their stable levels and delivery to tissues. This glycoprotein is crucial for regulating the distribution of thyroid hormones, which affect metabolism, growth, and development. Variations in SERPINA7 levels or mutations in its gene can impact hormone availability and thyroid-related functions.