SLC38A1 and folate deficiency: The TPM protein expression of SLC38A2 (Sodium-coupled Neutral Amino acid Transporter 2, SNAT2, an isoform of the System A amino acid transporter) and SLC7A5 (Large neutral Amino acid Transporter, LAT1, a System L amino acid transporter isoform), but not SLC38A1 (SNAT1) or SLC7A8 (LAT2), was markedly decreased in response to maternal folate deficiency (Supplementary Figure 2c,d).