12545
We analyzed the activity of the enhancer , the promoter and the silencer of the human CD4 gene during T cell development using transgenic mice .
 ( DNA: promoter, None) , ( DNA: human CD4 gene, None) , ( DNA: CD4 gene, None) , ( DNA: silencer, 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:
 ( DNA: promoter, None) , ( DNA: human CD4 gene, None) , ( DNA: CD4 gene, None) , ( DNA: silencer, None) , ( DNA: enhancer, None) 