The Thyroid Hormone Receptor (THR) includes THRα and THRβ, belonging to the nuclear receptor family, which comprises DNA binding domains and ligand binding domains. These receptors primarily localize in the cell nucleus and regulate gene expression mediated by thyroid hormones. THR is involved in regulating important biological processes such as metabolism, cardiac function, development, and growth. The expression of THR varies in different cells and tissues, and its activity is regulated by thyroid hormone levels. Mutations or dysregulation in THR genes are associated with various diseases, including metabolic disorders, cardiovascular diseases, and developmental abnormalities.