25682
Hepatic mRNA was extracted , and the relative expression of clock genes ( Per1 , Per2 , Bmal1 , Clock , Cry1 ) , as well as CCGs ( Dbp , E4bp4 , RevErb alpha , Ror alpha , Ppar gamma ) , was analyzed by reverse transcription followed by real - time polymerase chain reaction .
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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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