4434
Although IL-2 and IFN-alpha activated STAT1 alpha and STAT5 , IL-2 predominantly activated STAT5 , while IFN-alpha predominantly activated STAT1 alpha .
 ( protein: IL-2, None) , ( protein: STAT1 alpha, None) , ( protein: STAT5, None) , ( protein: IL-2, None) , ( protein: STAT5, None) , ( protein: IFN-alpha, None) , ( protein: STAT1 alpha, None) , ( protein: IFN-alpha, 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: IL-2, None) , ( protein: STAT1 alpha, None) , ( protein: STAT5, None) , ( protein: IL-2, None) , ( protein: STAT5, None) , ( protein: IFN-alpha, None) , ( protein: STAT1 alpha, None) , ( protein: IFN-alpha, None) 