6052
Reporter gene experiments finally showed that transcription from promoters of STAT5 target genes can be specifically induced by challenging cells with IL-4 , and that both STAT5a and STAT5b can contribute to IL-4 -triggered transcriptional control .
 IL-4, STAT5b, STAT5, IL-4, STAT5a
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, STAT5b, STAT5, IL-4, STAT5a