3685
HIV-1 infection resulted in constitutive, low-level expression of type 1 interferon ( IFN ) at the mRNA level .
 ( protein: IFN, None) , ( protein: type 1 interferon, 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: IFN, None) , ( protein: type 1 interferon, None) 