In contrast, Lin and Schumaf reported the protective effect of COX2 rs689466 and rs5273 polymorphisms against colorectal neoplasms (26, 33), and some other studies reported an increased risk of CRC carriers of some COX2 polymorphisms such as rs689466 and rs20417 (31, 32, 35, 43). The gene discussed is PTGS2; the disease is colorectal carcinoma.