3143
Wistar rats ( 180 g ) were treated by DEN alone or by DEN + PB during 2 , 4 and 6 weeks according to our schedule for hepatocarcinogenesis .
 Chemical: DEN; Chemical: DEN; Chemical: PB; Disease: hepatocarcinogenesis
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: DEN; Chemical: DEN; Chemical: PB; Disease: hepatocarcinogenesis