12517
Experiments in COS-1 and EL-4 cells confirmed both hypotheses and revealed that the second factor activated by Tpl-2 is NF-kappaB .
 ( cell line: EL-4 cells, None) , ( cell line: COS-1, None) , ( protein: NF-kappaB, None) , ( protein: Tpl-2, 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:
 ( cell line: EL-4 cells, None) , ( cell line: COS-1, None) , ( protein: NF-kappaB, None) , ( protein: Tpl-2, None) 