28533
Quantitative real - time RT - PCR showed that mRNA levels of estrogen receptor alpha ( ER - alpha ) and vitellogenin - I ( VTG - I ) in the liver of females were significantly down - regulated , while those of vitellogenin - I ( VTG - I ) in the liver of males were significantly up - regulated at all concentrations .
 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: estrogen