7451
In the human, this may also occur via IFN-alpha , which is able to activate Stat4 .
 Stat4, IFN-alpha
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:
 Stat4, IFN-alpha