These findings are corroborated by work of Constância et al. (2002) who generated the placental-specific Igf2 knockout mouse (P0) by deletion of a paternally imprinted Igf2 promoter; this mouse bears IUGR fetuses at term and led to a diminution in system A transport but an increase in Glut3 expression. This evidence concerns the gene IGF2 and fetal growth restriction.