5139
Recent studies indicate that HTLV-1 Tax targets IkappaBalpha to the ubiquitin- proteasome pathway .
 IkappaBalpha, Tax
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:
 IkappaBalpha, Tax