6105
Repression is alleviated when the two ( for E2 ) or three ( for E2 - C ) promoter - proximal copies of E2 - RS are mutated .
 E2, E2 - C, E2
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 E2, E2 - C, E2