5749
Moreover T cell proliferation was unaffected by the addition of blocking Abs to both IL-2 and the IL-2 receptor , demonstrating that this form of costimulation by CD28 was independent of IL-2 .
 ( protein: IL-2, None) , ( protein: IL-2, None) , ( protein: IL-2 receptor, None) , ( protein: CD28, None) , ( protein: IL-2, None) , ( protein: Abs, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( protein: IL-2, None) , ( protein: IL-2, None) , ( protein: IL-2 receptor, None) , ( protein: CD28, None) , ( protein: IL-2, None) , ( protein: Abs, None) 