4470
An F1 hybrid of F344 and BN exhibited significant pituitary growth after 10 weeks of DES treatment with an average mass of 26 . 3 + / - 0 . 7 mg compared with 8 . 6 + / - 0 . 9 mg for untreated rats .
 Chemical: DES
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: DES