11620
Preliminary observations tend to correlate this CREF cell killing with the accumulation of the early viral proteins and/or viral DNA in the infected cells .
 ( DNA: viral DNA, None) , ( cell type: infected cells, None) , ( protein: early viral proteins, 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: viral DNA, None) , ( cell type: infected cells, None) , ( protein: early viral proteins, None) 