12139
We demonstrate here the interaction of RANK with tumor necrosis factor receptor-associated factors ( TRAFs ) 1 , 2 , 3 , 5 , and 6 both in vitro and in cells.
 RANK, TRAFs
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:
 RANK, TRAFs