Solute carrier organic anion transporter family member 1C1 (SLCO1C1)

Mediates the Na(+)-independent high affinity transport of organic anions such as the thyroid hormones thyroxine (T4) and rT3. Other potential substrates, such as triiodothyronine (T3), 17-beta-glucuronosyl estradiol, estrone-3-sulfate and sulfobromophthalein (BSP) are transported with much lower efficiency.

May play a signifiant part in regulating T4 flux into and out of the brain (By similarity). .