12750
In group I BL cells , containing low levels of NF-kappaB , only RBP binding was observed in EMSAs , whereas NF-kappaB binding could be demonstrated in EBV-transformed B cell lines containing high levels of activated NF-kappaB .
 ( protein: NF-kappaB, None) , ( protein: NF-kappaB, None) , ( cell line: EBV-transformed B cell lines, None) , ( cell line: group I BL cells, None) , ( protein: NF-kappaB, None) , ( protein: RBP, 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: NF-kappaB, None) , ( protein: NF-kappaB, None) , ( cell line: EBV-transformed B cell lines, None) , ( cell line: group I BL cells, None) , ( protein: NF-kappaB, None) , ( protein: RBP, None) 