14736
Thus, tyrosine phosphorylation is an important and perhaps mandatory proximal step in the activation of the protein kinase C signaling cascade in human B-lymphocyte precursors .
 ( protein: protein kinase C, None) , ( cell type: human B-lymphocyte precursors, 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: protein kinase C, None) , ( cell type: human B-lymphocyte precursors, None) 