3849
The CRE site in the bcl-2 promoter appears to play a major role in the induction of bcl-2 expression during the activation of mature B cells and during the rescue of immature B cells from apoptosis.
 immature B cells, CRE site, bcl-2 promoter, mature B cells, B cells, bcl-2, B cells
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 B cells, CRE site, bcl-2 promoter, mature B cells, B cells, bcl-2, B cells