3285
In these cells, nuclear factors involved in activation of the HIV-1 LTR , which contains the transcriptional control elements of the virus, are unknown.
 ( DNA: HIV-1 LTR, None) , ( protein: nuclear factors, None) , ( DNA: transcriptional control elements, 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: HIV-1 LTR, None) , ( protein: nuclear factors, None) , ( DNA: transcriptional control elements, None) 