7184
However, CTLA-4 ligation did not appear to affect the CD28 -mediated stabilization of IL-2 mRNA .
 ( RNA: IL-2 mRNA, None) , ( protein: CTLA-4, None) , ( protein: CD28, None) , ( protein: IL-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:
 ( RNA: IL-2 mRNA, None) , ( protein: CTLA-4, None) , ( protein: CD28, None) , ( protein: IL-2, None) 