2387
MHC class II molecules also serve as receptors for B-cell stimulation by microbial superantigens .
 ( protein: microbial superantigens, None) , ( cell type: B-cell, None) , ( protein: MHC class II, 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: microbial superantigens, None) , ( cell type: B-cell, None) , ( protein: MHC class II, None) 