7640
The observed phenomena might be caused by downregulation of an IL-2R regulation gene , and might play a key role in the expansion of choriocarcinoma , and possibly in the survival of the fetal allograft .
 ( DNA: IL-2R regulation gene, None) , ( protein: IL-2R, 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: IL-2R regulation gene, None) , ( protein: IL-2R, None) 