As a specific inhibitor of cyclooxygenase-2 (COX-2) and a non-steroidal anti-inflammatory drug, etoricoxib has analgesic, anti-inflammatory, and antipyretic effects [4], which has been widely used to relieve pain, reduce morning stiffness, and improve the joint function of OA and rheumatoid arthritis patients. This evidence concerns the gene PTGS2 and rheumatoid arthritis.