1934
Activation of the enhancer in non- B cells upon overexpression of the basic helix-loop-helix (bHLH) protein E2A appears to be mediated not only by the binding of E2A to its cognate E box but also by the resulting displacement of a repressor from that same site.
 ( cell type: non- B cells, None) , ( protein: repressor, None) , ( protein: E2A, None) , ( protein: E2A, None) , ( cell type: B cells, None) , ( DNA: E box, None) , ( protein: basic helix-loop-helix (bHLH) protein, None) , ( DNA: enhancer, 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:
 ( cell type: non- B cells, None) , ( protein: repressor, None) , ( protein: E2A, None) , ( protein: E2A, None) , ( cell type: B cells, None) , ( DNA: E box, None) , ( protein: basic helix-loop-helix (bHLH) protein, None) , ( DNA: enhancer, None) 