2557
A GC box containing a binding site for Sp1 was identified ( nt 4623 to 4631 ).
 binding site, nt 4623 to 4631, GC box, Sp1
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:
 binding site, nt 4623 to 4631, GC box, Sp1