2379
Stimulation of the CD28 cell surface molecule delivers costimulatory signals essential for lymphokine production in activated T cells via a conserved sequence element found in the promoter of several lymphokine genes .
 ( protein: lymphokine, None) , ( protein: CD28 cell surface molecule, None) , ( protein: CD28, None) , ( protein: lymphokine, None) , ( DNA: lymphokine genes, None) , ( cell type: activated T cells, None) , ( DNA: promoter, None) , ( DNA: conserved sequence element, 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: lymphokine, None) , ( protein: CD28 cell surface molecule, None) , ( protein: CD28, None) , ( protein: lymphokine, None) , ( DNA: lymphokine genes, None) , ( cell type: activated T cells, None) , ( DNA: promoter, None) , ( DNA: conserved sequence element, None) 