12551
Unexpectedly, the CD4 silencer is also active in CD4+ CD8int/- cells of the thymus , implying that an anti-silencer may be required to resume CD4 expression in this cell population.
 ( cell type: CD4+ CD8int/- cells, None) , ( protein: CD4, None) , ( DNA: CD4 silencer, 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: CD4+ CD8int/- cells, None) , ( protein: CD4, None) , ( DNA: CD4 silencer, None) 