3648
Because the -180 site is not required for trans-activation , it was possible to confirm by mutation in the normal mouse IL-2 enhancer that this site is absolutely essential for anergy induction .
 ( DNA: -180 site, None) , ( DNA: IL-2 enhancer, None) , ( DNA: mouse IL-2 enhancer, 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:
 ( DNA: -180 site, None) , ( DNA: IL-2 enhancer, None) , ( DNA: mouse IL-2 enhancer, None) , ( protein: IL-2, None) 