RESULTS: Aspirin, diclofenac, indomethacin, ketoprofen, meclofenamic acid, and piroxicam had little selectivity toward COX isozymes, whereas << NS398 >>, carprofen, tolfenamic acid, nimesulide, and etodolac had more than 5 times greater preference for inhibiting COX-2 than [[ COX-1 ]].