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For model development , we used plasma 17 beta - estradiol ( E2 ) concentrations and ovarian cytochrome P450 ( CYP ) 19A aromatase mRNA data from two time - course experiments , each of which included both an exposure and a depuration phase , and plasma E2 data from a third 4 - day study .
 Chemical: 17 beta - estradiol
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: 17 beta - estradiol