7780
In the GDC , earlier responses were observed and the fold - change magnitude was generally much higher : transcription of all target genes increased significantly ( or non - significantly for cat ) after 5 h of exposure , and went back to control levels afterwards , suggesting the onset of an early response to oxidative stress associated to the unbalance of reactive oxygen species ( ROS ) in hepatocytes .
 Chemical: oxygen
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: oxygen