4100
To address possible mechanisms that could explain this selective activity of c-ErbB , we analyzed the ability of these receptors to activate the different members of the Stat transcription factor family .
 ( protein: c-ErbB, None) , ( protein: Stat transcription factor family, 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: c-ErbB, None) , ( protein: Stat transcription factor family, None) 