TG and metabolic disease: in 1967 (21), and some of the main causes of RTH include 1) mutation of the thyroid hormone receptor, 2) binding disorder of the thyroid hormone and its receptor, and 3) abnormal post-binding action of the thyroid hormone receptors, etc., leading to the insensitivity of the tissues to the thyroid hormone, thus causing metabolic disorders, thyroid dysfunction, etc. In addition to the brain, testis, and lymph, thyroid hormone receptors are widely expressed in diverse tissues, organs, and cells.