9451
Ig heavy chain class switching is directed by cytokines inducing transcription from unrearranged CH genes .
 Ig heavy chain, CH genes, cytokines
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:
 Ig heavy chain, CH genes, cytokines