5418
The regulation of collagenase expression is cell-type specific; bacterial LPS and zymosan , a yeast cell wall derivative , are potent inducers of collagenase expression in macrophages , but do not alter fibroblast collagenase expression .
 fibroblast, collagenase, collagenase, collagenase, macrophages
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:
 fibroblast, collagenase, collagenase, collagenase, macrophages