25930
We compared effects of continuous PTH on bone marrow stromal cells ( BMSCs ) and primary OBs ( POBs ) from Cox - 2 KO mice , mice with deletion of PGE2 receptors ( Ptger4 and Ptger2 KO mice ) , and WT controls .
 Chemical: PGE2
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: PGE2