10456
Therefore, we have constructed a single cDNA that encodes a single-chain protein , called Flexi-12 , which retains all of the biological characteristics of recombinant IL-12 ( rIL-12 ).
 ( DNA: cDNA, None) , ( protein: IL-12, None) , ( protein: single-chain protein, None) , ( protein: rIL-12, None) , ( protein: Flexi-12, 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:
 ( DNA: cDNA, None) , ( protein: IL-12, None) , ( protein: single-chain protein, None) , ( protein: rIL-12, None) , ( protein: Flexi-12, None) 