2114
To determine in vivo the ligand dependency and relative roles of different ER alpha domains for the osteogenic response to mechanical loading , gene - targeted mouse models with ( 1 ) a complete ER alpha inactivation ( ER alpha ( - / - ) ) , ( 2 ) specific inactivation of activation function 1 ( AF - 1 ) in ER alpha ( ER alpha AF - 1 ( 0 ) ) , or ( 3 ) specific inactivation of ER alpha AF - 2 ( ER alpha AF - 2 ( 0 ) ) were subjected to axial loading of tibia , in the presence or absence ( ovariectomy [ ovx ] ) of endogenous E2 .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None