12149
In Th2 cells, IL-4 gene expression is tightly controlled at the level of transcription by the coordinated binding of multiple transcription factors to regulatory elements in the proximal promoter region .
 transcription factors, promoter region, IL-4
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:
 transcription factors, promoter region, IL-4