13750
Down - regulation of PRX1 reduced the inhibitory effect of CO on OC formation and sustained the ROS levels induced by RANKL , suggesting that CO reduces generation of ROS and scavenges ROS to inhibit osteoclastogenesis .
 Chemical: CO; Chemical: CO
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: CO; Chemical: CO