2556
Factors binding to site C ( nt 4681 to 4701 ) had a DNA-binding specificity similar to that of factors binding to site B , except for PU.1/Spi-1 .
 site C, PU.1/Spi-1, nt 4681 to 4701, site B
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:
 site C, PU.1/Spi-1, nt 4681 to 4701, site B