1936
By employing a derivative E box that binds ZEB but not E2A , we have shown that the repressor is active in B cells and the IgH enhancer is silenced in the absence of binding competition by bHLH proteins .
 ( DNA: E box, None) , ( protein: ZEB, None) , ( cell type: B cells, None) , ( protein: repressor, None) , ( protein: E2A, None) , ( DNA: IgH enhancer, None) , ( protein: bHLH proteins, 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:
 ( DNA: E box, None) , ( protein: ZEB, None) , ( cell type: B cells, None) , ( protein: repressor, None) , ( protein: E2A, None) , ( DNA: IgH enhancer, None) , ( protein: bHLH proteins, None) 