Solute carrier organic anion transporter family member 1B3 (SLCO1B3) also known as organic anion-transporting polypeptide 1B3 (OATP1B3) is a protein that in humans is encoded by the SLCO1B3 gene. OATP1B3 is a 12-transmembrane domain influx transporter. Normally expressed in the liver, the transporter functions to uptake large, non-polar drugs and hormones from the portal vein. Clinical significance OATP1B3 has also been identified as a transporter aberrantly expressed in prostate cancer and implicated in prostate cancer progression. Increasing mRNA expression of OATP1B3 was also correlated to prostate cancer Gleason score. In addition, lower expression of OATP1B3 mRNA was also detected in testicular cancer. Substrates Small molecules that are transported by SLCO1B3 include: Amanitin Atrasentan Bilirubin Bosentan BQ-123 Bromsulphthalein (BSP) CDCA-NBD Cholate (CA) Cholecystokinin octapeptide (CCK-8) Dehydroepiandroserone-3-sulfate (DHEAS) Deltorphin II Demethylphalloin Digoxin Docetaxel [D-penicillamine2,5]enkephalin (DPDPE) Enalapril Estradiol-17β-glucuronide 5–25 Estrone-3-sulfate Fexofenadine Fluvastatin Fluo-3 Glutathione (GSH) Glycocholate (GCA) Glycoursodeoxycholate (GUDCA) Irinotecan Leukotriene C4 (LTC4) Methotrexate Microcystin Monoglyucuronosyl Olmesartan Ouabain Paclitaxel Phalloidin Pitavastatin Rifampicin Ro 48-5033 (Bosentan metabolite) Rosuvastatin SN-38 Taurocholate (TCA) Taurochenodeoxycholate (TCDCA) Taurodeoxycholate (TDCA) Tauroursodeoxycholate (TUDCA) Telmisartan Thyroxine (T4) TR-14035 Triiodothyronine (T3) Valsartan See also Solute carrier family References Further reading Solute carrier family