13069
Here, cytokine -induced activation of Stat3 in previously activated CD4(+) human T cells was examined using Stat3 antibodies directed against different regions of Stat3 .
 ( protein: Stat3, None) , ( cell type: CD4(+) human T cells, None) , ( protein: Stat3, None) , ( protein: cytokine, None) , ( protein: Stat3, 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: Stat3, None) , ( cell type: CD4(+) human T cells, None) , ( protein: Stat3, None) , ( protein: cytokine, None) , ( protein: Stat3, None) 