SLC5A5 and hypothyroidism: Various mechanisms such as the inhibition of thyroid peroxidase activity [14], the block of iodine uptake [due to a direct effect of sunitinib on sodium iodide symporter (NIS)], the block of TSH receptor [15], and alterations in thyroxine/triiodothyronine (T4/T3) metabolism (related to increased activity of type 3 Deiodinase) [16] have been proposed as hypothyroidism-inducing.