1997
In this regard, the cytokine interleukin 6 ( IL-6 ) may play a role in the clinical manifestations and pathological events of tuberculosis infection .
 tuberculosis infection, interleukin 6, IL-6, cytokine
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:
 tuberculosis infection, interleukin 6, IL-6, cytokine