3144
After the end of the treatment , the number and the size of induced PAS positive preneoplastic foci was significantly reduced when PB was given simultaneously with DEN for 4 and 6 weeks .
 Disease: preneoplastic foci; Chemical: PB; Chemical: DEN
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:
 Disease: preneoplastic foci; Chemical: PB; Chemical: DEN