4695
Neutralizing antiserum against IFN-gamma , but not other cytokines tested, blocked activation of the factor almost completely, and IFN-gamma was found in the culture supernatants of stimulated cells at levels at which recombinant IFN-gamma could activate the factor in naive cells .
 ( protein: IFN-gamma, None) , ( protein: cytokines, None) , ( protein: IFN-gamma, None) , ( cell type: naive cells, None) , ( protein: IFN-gamma, None) , ( cell line: stimulated cells, 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-gamma, None) , ( protein: cytokines, None) , ( protein: IFN-gamma, None) , ( cell type: naive cells, None) , ( protein: IFN-gamma, None) , ( cell line: stimulated cells, None) 