13613
Low concentrations of RA inhibiting IgE synthesis (10(-10) mol/L) affected neither B-cell proliferation nor the production of IgA , IgG , and IgM .
 IgG, IgM, IgA, 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:
 IgG, IgM, IgA, IgE