5005
The aim of this study was to evaluate the effects of TCDD administered to pregnant mice at two different doses ( 2 - 10 ng / kg / day ) , on imprinted genes in the male offspring .
 TCDD
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 TCDD