observed hypermethylation of the promoters of glucokinase (Gck) and urocortin 3 (Ucn3) with concurrent hypomethylation of glycolytic enzymes/dedifferentiation markers hexokinase 1 and 2 (Hk1/2) and lactate dehydrogenase (Ldha) in immature β-cells mirroring the early transcriptional changes with HF diet (79). The gene discussed is GCK; the disease is hydrops fetalis.