Although our results differ from the study reporting decreased SLC6A4 mRNA levels in placentas obtained from GDM as compared to non-GDM pregnancies [12], they are in line with an in vitro study showing that diabetes-like concentrations of glucose increase transcription of the SLC6A4 gene in human placental choriocarcinoma (JAR) cells [58]. This evidence concerns the gene SLC6A4 and diabetes mellitus.