26761
Estrogen receptor ( ER ) beta is highly expressed in ovarian granulosa cells and mice lacking ER beta ( beta ERKO ) are subfertile due to inefficient ovulation .
 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