4704
The Cd 2 - induced down - regulation of Cyp1a1 , Gsta2 , and Nqo1 mRNA was not antagonized by pure anti - estrogen ( 2 . 5 mg / kg b . wt ZK191703 s . c . , ZK ) .
 Chemical: Cd; Chemical: estrogen
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: Cd; Chemical: estrogen