PTGS2 and colorectal adenoma: Colorectal adenomas are known precursor lesions of CRC with similar risk factors.6,7,8 Thus efforts are required to interrupt the possibility of the progression of adenomas to colorectal cancer.6 The expression of COX-2 provides vital information for the uses of nonsteroidal anti-inflammatory drugs in the prevention and treatment of adenoma and hurting adenoma progression into carcinoma.