2314
NF-kB levels were higher in unstimulated U1 cells as compared to the parent cell line U937 .
 ( cell line: U937, None) , ( cell line: unstimulated U1 cells, None) , ( protein: NF-kB, None) , ( cell line: parent cell line, 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: U937, None) , ( cell line: unstimulated U1 cells, None) , ( protein: NF-kB, None) , ( cell line: parent cell line, None) 