2770
Additionally, IFN-gamma activity but not IL-1 , IL-2 , or IL-4 activity was present in culture supernatants 72 h after R24 stimulation .
 IFN-gamma, R24
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:
 IFN-gamma, R24