4523
Ectopic expression of the dominant negative C/EBP protein LIP inhibited HIV-1 mRNA and virus production in activated U1 cells , demonstrating that C/EBP proteins are required for provirus induction .
 ( protein: C/EBP proteins, None) , ( cell line: activated U1 cells, None) , ( protein: C/EBP protein LIP, 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: C/EBP proteins, None) , ( cell line: activated U1 cells, None) , ( protein: C/EBP protein LIP, None) 