2947
EL-4 cells were transfected with a plasmid containing the IL-2 promoter and enhancer region linked to the chloramphenicol acetyltransferase ( CAT ) reporter gene .
 ( protein: CAT, None) , ( DNA: enhancer region, None) , ( DNA: chloramphenicol acetyltransferase ( CAT ) reporter gene, None) , ( protein: chloramphenicol acetyltransferase, None) , ( DNA: IL-2 promoter, None) , ( cell type: EL-4 cells, 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: CAT, None) , ( DNA: enhancer region, None) , ( DNA: chloramphenicol acetyltransferase ( CAT ) reporter gene, None) , ( protein: chloramphenicol acetyltransferase, None) , ( DNA: IL-2 promoter, None) , ( cell type: EL-4 cells, None) 