8634
Two CAGGTG E-boxes , located at the 5'- and 3'- ends of the silencer, were necessary for this silencer activity .
 CAGGTG E-boxes
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 CAGGTG E-boxes