7445
Much of our focus in understanding Th1/Th2 development has been on the signals delivered by IL-12 and IL-4 as final determinants of terminal T cell differentiation .
 IL-4, IL-12
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:
 IL-4, IL-12