10470
Cyclooxygenase - 2 ( COX - 2 ) inhibitors have been the focus of medicinal chemistry efforts for years , and many compounds that exhibit high selectivity and affinity have been developed .
 None
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