913
Mutations of the AML1- or LBF4- binding sites had no effect on EBNA-2 transactivation , whereas mutation of the PU.1 -binding site completely eliminated EBNA-2 responses .
 PU.1, EBNA-2, PU.1 -binding site, EBNA-2
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:
 PU.1, EBNA-2, PU.1 -binding site, EBNA-2