13730
Therefore, we also evaluated activation of the MAP kinase extracellular signal-regulated kinase ( ERK ) 2 by the phorbol ester phorbol 12-myristate 13-acetate ( PMA ).
 ( protein: ERK, None) , ( protein: MAP kinase extracellular signal-regulated kinase, None) , ( protein: MAP kinase extracellular signal-regulated kinase ( ERK ) 2, 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: ERK, None) , ( protein: MAP kinase extracellular signal-regulated kinase, None) , ( protein: MAP kinase extracellular signal-regulated kinase ( ERK ) 2, None) 