2338
Interleukin 2 ( IL-2 ) is an important lymphokine required in the process of T cell activation , proliferation , clonal expansion and differentiation .
 IL-2, Interleukin 2, lymphokine
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-2, Interleukin 2, lymphokine