14674
Endothelial cells ( EC ) act as APC for resting PBL in vitro, and may have important roles in vivo in the pathogenesis of allograft rejection and delayed hypersensitivity .
 ( cell type: resting PBL, None) , ( cell type: Endothelial cells, None) , ( cell type: PBL, None) , ( cell type: EC, 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:
 ( cell type: resting PBL, None) , ( cell type: Endothelial cells, None) , ( cell type: PBL, None) , ( cell type: EC, None) 