522
Since CIITA overexpression in normal cells did not increase class II expression , we propose that initiation of CIITA expression serves as the on-off switch, while availability of downstream interactor (s) limits transcription .
 ( protein: CIITA, None) , ( protein: CIITA, None) , ( cell type: normal 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: CIITA, None) , ( protein: CIITA, None) , ( cell type: normal cells, None) 