7785
Expression of GrpL is restricted to hematopoietic tissues , and it is distinguished from Grb2 by having a proline -rich region .
 ( protein: Grb2, None) , ( protein: proline -rich region, None) , ( protein: GrpL, 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: Grb2, None) , ( protein: proline -rich region, None) , ( protein: GrpL, None) 