8391
These are the long terminal repeat ( LTR ) promoter , which regulates expression of the viral structural proteins , and a second internal promoter , located towards the 3 ' end of the env gene , that directs expression of the viral auxiliary proteins .
 GENE: env gene
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
 Entities: env gene 
Answer:
 GENE: env gene