3161
Here we demonstrate that both in vitro-translated PU.1 and PU.1 from nuclear extracts bind to a specific site in the M-CSF receptor promoter just upstream from the major transcription initiation site .
 M-CSF receptor, major transcription initiation site, PU.1, PU.1, vitro-translated PU.1, M-CSF, M-CSF receptor promoter
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:
 M-CSF receptor, major transcription initiation site, PU.1, PU.1, vitro-translated PU.1, M-CSF, M-CSF receptor promoter