12902
Microarray analysis identified four miRNAs that were differentially expressed in postexposure compared with baseline samples , including miR - 421 ( FC = 2 . 81 , p < 0 . 001 ) , miR - 146a ( FC = 2 . 62 , p = 0 . 007 ) , miR - 29a ( FC = 2 . 91 , p < 0 . 001 ) , and let - 7g ( FC = 2 . 73 , p = 0 . 019 ) .
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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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