7773
Activation of MHC class II promoters requires binding of at least three distinct multi-protein complexes ( RFX , X2BP and NF-Y ).
 ( protein: X2BP, None) , ( DNA: MHC class II promoters, None) , ( protein: RFX, None) , ( cell type: MHC class II, None) , ( protein: NF-Y, None) , ( protein: multi-protein complexes, 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: X2BP, None) , ( DNA: MHC class II promoters, None) , ( protein: RFX, None) , ( cell type: MHC class II, None) , ( protein: NF-Y, None) , ( protein: multi-protein complexes, None) 