1951
Previous work has shown that spleen necrosis virus ( SNV ) long terminal repeats ( LTRs ) are associated with Rex / Rex - responsive element - independent expression of bovine leukemia virus RNA and supports the hypothesis that SNV RNA contains a cis - acting element that interacts with cellular Rex - like proteins .
 GENE: spleen necrosis virus ( SNV ) long terminal repeats; GENE: Rex; GENE: Rex; GENE: cellular Rex - like proteins
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: spleen necrosis virus ( SNV ) long terminal repeats; GENE: Rex; GENE: Rex; GENE: cellular Rex - like proteins