556
In seven EBV-B cell clones or lines differing in their capacity to secrete IL-2 , the activity of the IL-2 promoter correlated well with the status of IL-2 secretion .
 ( protein: IL-2, None) , ( protein: IL-2, None) , ( protein: IL-2, None) , ( cell line: EBV-B cell clones, None) , ( DNA: IL-2 promoter, 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, None) , ( cell line: EBV-B cell clones, None) , ( DNA: IL-2 promoter, None) 