The human placenta displays a wide range of transporters for thyroid hormones from early gestation: MCT8, MCT10, LAT1, LAT2, OATP1A2 and OATP4A1; the observed expression patterns are different between pregnancies with normal physiology and pregnancies affected with intrauterine growth restriction [44]. The gene discussed is SLCO4A1; the disease is fetal growth restriction.