The data presented here show that B6 embryos are specifically resistant to maternal hyperglycemia just prior to induction of neural tube formation, independent of other metabolic disturbances of diabetes, and this is not due to differences in expression of Glut2 mRNA, which encodes the high KM glucose transporter that is required for susceptibility to hyperglycemia-induced NTDs [5]. The gene discussed is SLC2A2; the disease is diabetes mellitus.