10486
Emphasis is placed on cytokines that have been studied in periodontitis , principally TNF-alpha , IL-1 , IL-6 , IL-8 and beta-interferon .
 IL-6, TNF-alpha, IL-1, cytokines, beta-interferon, IL-8
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:
 IL-6, TNF-alpha, IL-1, cytokines, beta-interferon, IL-8