2706
The molecular mass of these factors is approximately 28 kDa , and their DNA binding characteristics are indistinguishable from those of the novel nuclear factor MS-2 .
 nuclear factor, MS-2
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:
 nuclear factor, MS-2