1871
In vivo protein-DNA contacts are detectable at Ii kappa B-1 in cell lines in which this site is functional as either a positive or negative regulator .
 cell lines, Ii kappa B-1
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:
 cell lines, Ii kappa B-1