24994
It was discovered that the most active compound 21 released high levels of NO selectively in HCC cells but not in the normal cells , and exhibited potent antiproliferative activity in vitro as well as remarkable tumor - retarding effects in vivo .
 Chemical: NO
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: NO