7193
The hormone delayed terminal differentiation into erythrocytes , which was assayed by morphology, hemoglobin accumulation , and the expression of genes characteristic for immature cells .
 immature cells, hemoglobin, erythrocytes
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:
 immature cells, hemoglobin, erythrocytes