1187
In our studies , we utilized HIV - 1 HXB2 and HIV - 1 Z2Z6 core enhancers because the Z2Z6 strain has a single point mutation flanking the right ETS - binding site .
 GENE: HXB2; GENE: Z2Z6 core enhancers; GENE: Z2Z6; GENE: ETS - binding site
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: HXB2; GENE: Z2Z6 core enhancers; GENE: Z2Z6; GENE: ETS - binding site