The SERPINA7 gene in people encodes the globulin protein known as thyroxine-binding globulin. TBG attaches circulating thyroid hormones. It is one of three transport proteins that move the thyroid hormones Thyroxine (T4) and Triodothyronine (T3) through the circulation, along with transthyretin and serum albumin. TBG, the least abundant of these three proteins compared to transthyretin and albumin, which also bind T3 and T4 in circulation, has the greatest affinity for both T4 and T3 metabolites.
