19964
Moreover , angiogenesis , macrophage accumulation , and the levels of VEGF and TGF - beta were comparable between Plg ( + / + ) and Plg ( - / - ) mice in heterotopic ossification .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None