Since the reaction catalyzed by PTGS1 and 2 (Prostaglandin-Endoperoxide Synthase 1 and 2, commonly known as COX-1 and COX-2) is the first step in prostaglandin synthesis and known to be up-regulated in prostate cancer52, we used our tumor-specific metabolic network model to simulate additional metabolic liabilities that are driven by the PTGS reaction (Fig. 4B). This evidence concerns the gene PTGS1 and neoplasm.