The predominant function of the thyroid gland is to provide the hormones, thyroxine (T4), triiodothyronine (T3), that are crucial for the regulation of metabolic approaches, and calcitonin (1,2). The production of T3 and T4 depends on the appropriate tissue employer of thyroid epithelial cells, the thyrocytes, into functional and independent units, the follicles. These are composed of a unmarried layer of polarized thyrocytes that form a round structure delineating an internal area or lumen in which the thyrocyte secretory product, thyroglobulin (Tg), is saved in a colloidal form, for that reason called the colloid lumen. As thyrocytes speak via hole junctions, every follicle capabilities as an integrated unit.Thyroid hormone synthesis depends on apicobasal cell polarity that lets in the unique localization of channels, transporters, pumps, and enzymes at the correct membrane domains. Iodide from the bloodstream freely traverses the fenestrated endothelium of the thyroid capillaries and is taken up into thyrocytes via the basolaterally localized NIS, way to a Na+ gradient generated through the Na+/K+-ATPase. An alternative basolateral transporter, SLC26A7, has been recently mentioned to also manage iodide uptake, although its position might be oblique (3). Iodide diffuses freely inside thyrocytes and is next transported throughout the apical membrane into the colloid space through apically localized transporters along with anoctamin or pendrin (SLC26A4).