15198
The production of cytokines in bronchoalveolar lavage fluid and serum was measured using enzyme - labeled immunosorbent assay kits , and the expression levels of transforming growth factor - beta 1 and vascular endothelial growth factor were detected by immunohistochemistry .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
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