Any (1+, 2+) COX-2 expression was more common in non-serrated adenomas (60% = 307/515) than in hyperplastic polyps (13% = 3/24, p < 0.0001), and serrated lesions including SSAs and mixed polyps (25% = 3/12, p = 0.03) (Table 1, Figure 4). Here, PTGS2 is linked to adenoma.