1733
Here we report that CD28 engagement, however, exerts opposite effects on the transcription factor AP-1 .
 ( protein: transcription factor, None) , ( protein: AP-1, None) , ( protein: transcription factor AP-1, None) , ( protein: CD28, 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: transcription factor, None) , ( protein: AP-1, None) , ( protein: transcription factor AP-1, None) , ( protein: CD28, None) 