11663
In this paper, we demonstrate that the activation of NF-kappaB by LPS in a promonocytic cell line ( U937 ) followed a rather slow kinetics, depending on the rate of IkappaB-alpha inhibitor hydrolysis .
 U937, NF-kappaB, IkappaB-alpha, promonocytic cell line
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:
 U937, NF-kappaB, IkappaB-alpha, promonocytic cell line