7862
Cytokine expression by immune system cells plays an important role in the regulation of the immune response .
 protein: Cytokine
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
 Entities: Cytokine 
Answer:
 protein: Cytokine