4873
In conclusion , the characteristic gene expression signatures from a rat model system could be used as predictable and discernible gene - based biomarkers for the detection and prediction of PAHs , and these molecular markers may provide insights into the underlying mechanisms for genotoxicity of exposure to PAHs from environmental aspect .
 Chemical: PAHs; Chemical: PAHs
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: PAHs; Chemical: PAHs