13681
METHODS AND RESULTS: Monolayers of human umbilical vein endothelial cells were incubated with nonstimulated or ADP-activated platelets for 6 hours, and secretion of MCP-1 and surface expression of ICAM-1 were determined by ELISA and flow cytometry , respectively.
 ( cell type: human umbilical vein endothelial cells, None) , ( protein: MCP-1, None) , ( cell type: endothelial cells, None) , ( protein: ICAM-1, None) , ( cell type: ADP-activated platelets, 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: human umbilical vein endothelial cells, None) , ( protein: MCP-1, None) , ( cell type: endothelial cells, None) , ( protein: ICAM-1, None) , ( cell type: ADP-activated platelets, None) 