3905
Culture supernatants from uninduced U937 cells were also found to activate an ISRE cloned upstream of the luciferase reporter gene , indicating the presence of endogenous IFN activity equivalent to approximately 0.3 to 0.5 IU/mL.
 ( protein: endogenous IFN, None) , ( cell line: uninduced U937 cells, None) , ( DNA: ISRE, None) , ( protein: luciferase, None) , ( DNA: luciferase reporter gene, 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: endogenous IFN, None) , ( cell line: uninduced U937 cells, None) , ( DNA: ISRE, None) , ( protein: luciferase, None) , ( DNA: luciferase reporter gene, None) 