12848
These results strongly suggest that the signaling pathway from Fc receptors leading to expression of different genes important to leukocyte biology, initiates with tyrosine kinases and requires MAPK activation ; but in contrast to other tyrosine kinase receptors , FcR -mediated MAPK activation does not involve Ras and Raf .
 ( protein: Fc receptors, None) , ( protein: tyrosine kinases, None) , ( protein: Ras, None) , ( protein: MAPK, None) , ( protein: tyrosine kinase receptors, None) , ( protein: MAPK, None) , ( protein: FcR, None) , ( protein: Raf, 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: Fc receptors, None) , ( protein: tyrosine kinases, None) , ( protein: Ras, None) , ( protein: MAPK, None) , ( protein: tyrosine kinase receptors, None) , ( protein: MAPK, None) , ( protein: FcR, None) , ( protein: Raf, None) 