2080
To investigate the role of this domain in the incorporation of the SIV Env into virions , we generated a series of SIV Env mutants carrying small in - frame deletions within the cytoplasmic domain .
 GENE: SIV Env; GENE: SIV Env mutants
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: SIV Env; GENE: SIV Env mutants