12967
S9a at 10 to 100 nM inhibited HIV production as potently as 3'-azido-3'-deoxythymidine ( AZT ), an inhibitor of viral reverse transcriptase .
 viral reverse transcriptase
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 viral reverse transcriptase