1220
In contrast, stat1 proteins were not tyrosine phosphorylated after IL-2 ligation , whereas tyrosine -phosphorylated stat1 proteins ( 91 and 84 kDa proteins ) were translocated to the nucleus following interferon-gamma treatment of HeLa cells .
 ( protein: interferon-gamma, None) , ( cell line: HeLa cells, None) , ( protein: tyrosine -phosphorylated stat1 proteins, None) , ( protein: IL-2, 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: interferon-gamma, None) , ( cell line: HeLa cells, None) , ( protein: tyrosine -phosphorylated stat1 proteins, None) , ( protein: IL-2, None) 