2273
The active compounds did not inhibit IL-1 -induced production of IL-6 in fibroblasts , showing the cell selectivity of the effect.
 fibroblasts, IL-6, IL-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:
 fibroblasts, IL-6, IL-1