10553
E2a- Pbx1 -induced apoptosis proceeded through a BCL2 -responsive checkpoint eventuating in PARP inactivation but did require p53 .
 ( protein: p53, None) , ( protein: Pbx1, None) , ( protein: PARP, None) , ( protein: BCL2, 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: p53, None) , ( protein: Pbx1, None) , ( protein: PARP, None) , ( protein: BCL2, None) 