6749
Interleukin (IL)-4 plays an important role in IgE synthesis in B cells and in Th2 differentiation in T cells .
 B cells, T cells, Interleukin (IL)-4, IgE
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:
 B cells, T cells, Interleukin (IL)-4, IgE