These authors evaluated the levels and localization of System L, alanine-serine-cysteine transporter 2 (ASCT2), and mTOR in the placental syncytiotrophoblast during FGR and preeclampsia and found a significant increase in the expression of System L amino acid transport proteins 4F2 cell-surface antigen heavy chain (4F2hc) and L-type amino acid transporter (LAT1) in FGR placenta compared with that in normal placenta. This evidence concerns the gene SLC1A5 and preeclampsia.