There is incontrovertible genetic and pharmacological evidence from rodent models that the inducible isoform of prostaglandin (PG) G/H synthase (PTGS2), also known as cyclooxygenase (COX), COX-2 plays an important role in the early stages of intestinal tumorigenesis during adenoma (or polyp) development1–3. Here, PTGS2 is linked to adenoma.