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At the same time there was no change in the level of expression of the cell surface antigenes CD33 , CD34 , CD45 , CD71 and glycophorin A .
 CD33, CD34, glycophorin A, cell surface antigenes, CD45, CD71
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:
 CD33, CD34, glycophorin A, cell surface antigenes, CD45, CD71