23655
We studied four candidate genes ( GSTM1 , DUSP22 , IFN - gamma , and IL - 4 ) for which altered promoter methylation has been previously investigated for relationships with a variety of other environmental exposures .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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