7472
This effect can be associated with the activation of specific hormone receptors, since we observed the expression of the estrogen receptor alpha (ER-alpha) , ER-beta , and progesterone receptor (PR) mRNAs ; the ER-alpha protein expression was confirmed by immunocytochemical analysis .
 ER-alpha
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 ER-alpha