11455
However, it is not clear which, if any, of these kinases are responsible for initiating IL-4-induced tyrosine phosphorylation of intracellular substrates in vivo.
 ( protein: intracellular substrates, 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: intracellular substrates, None) 