Interestingly, in a knockout mouse model, deletion of the gene transcript for placenta specific expression of Igf2 results in the reduction of placental growth while fetal growth is maintained in association with an up-regulation of glucose transporter (GLUT3) and amino acid transporter (SNAT2) during mid gestation, however IUGR still develops near term [59,60,61]. The gene discussed is SLC2A3; the disease is fetal growth restriction.