12300
CD2 , but not CD3 , cross-linking increased cAMP detected by competitive enzyme-linked immunosorbent assay ( ELISA ) approximately fourfold.
 ( protein: CD3, None) , ( protein: CD2, 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: CD3, None) , ( protein: CD2, None) 