7181
CTLA-4 engagement by mAbs inhibits, while CD28 enhances, IL-2 production and proliferation upon T cell activation .
 IL-2, CTLA-4, mAbs, CD28
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, CTLA-4, mAbs, CD28