8251
One of the prominent substrates for these kinases is the adaptor protein Cbl [3] and recent studies suggest that Cbl negatively regulates upstream kinases such as Syk and Zap-70 [4] [5].
 ( protein: adaptor protein, None) , ( protein: kinases, None) , ( protein: upstream kinases, None) , ( protein: Zap-70, None) , ( protein: Syk, None) , ( protein: Cbl, 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: adaptor protein, None) , ( protein: kinases, None) , ( protein: upstream kinases, None) , ( protein: Zap-70, None) , ( protein: Syk, None) , ( protein: Cbl, None) 