7480
Fourth , the 3 ' - region splice junctions of the MSRs during latent and productive infection were determined by sequencing RNA - PCR products generated with primers that flank the 3 ' splice region .
 MSRs
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 MSRs