8301
This observation was further confirmed in a rat air pouch model in vivo, in which both aspirin and triflusal inhibited PGE2 production (ID50 = 18.9 and 11.4 mg/kg p.o., respectively) but only triflusal -treated animals showed a decrease in COX-2 expression .
 ( protein: COX-2, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( protein: COX-2, None) 