4205
Our results suggest that PKA inhibits T cell activation by interfering with multiple events along the two signaling pathways operating downstream of the TCR and the CD28 co-receptor molecules .
 ( protein: CD28, None) , ( protein: PKA, None) , ( protein: CD28 co-receptor molecules, None) , ( protein: TCR, 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: CD28, None) , ( protein: PKA, None) , ( protein: CD28 co-receptor molecules, None) , ( protein: TCR, None) 