7740
Domain switch experiments reveal that C / EBP beta proteins containing either the leucine zipper or the activation domain of C / EBP alpha are unable to stimulate the 2D5 promoter yet are fully capable of transactivating an artificial promoter bearing a high - affinity C / EBP site .
 C / EBP beta proteins, C / EBP alpha, 2D5 promoter, C / EBP site
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 C / EBP beta proteins, C / EBP alpha, 2D5 promoter, C / EBP site