1045
These results support the hypothesis that EPO actively influences the programming of gene expression required for erythroid progenitor cell differentiation .
 EPO, erythroid progenitor cell
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:
 EPO, erythroid progenitor cell