Similarly, diet modulates the expression of genes encoding enzymes that are involved in eicosanoid metabolism, such as Prostaglandin endoperoxide synthase 2 (Ptgs2/Cox-2), Hydroxyprostaglandin dehydrogenase (Hpgd) and Cyp1a1. The enzymes encoded by these genes are involved in production and metabolism of prostaglandin E2, and our working model is that under conditions hyperglycemia and adverse diet, enzymes catalyzing PGE2 degradation are elevated to levels where they create a functional PGE2 deficiency, through increased catabolism of PGE2. This evidence concerns the gene HPGD and Hyperglycemia.