4081
The results suggest that a combination of the three proximal cis-acting elements may constitute a minimal region responsible for CTL-specific expression of perforin .
 ( protein: perforin, None) , ( DNA: cis-acting elements, 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: perforin, None) , ( DNA: cis-acting elements, None) 