13909
In particular, one class of helix-loop-helix proteins , termed E-proteins , have been implicated in the regulation of gene expression during B-cell development .
 ( protein: E-proteins, None) , ( protein: helix-loop-helix 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:
 ( protein: E-proteins, None) , ( protein: helix-loop-helix proteins, None) 