5569
We interpret this as a reflection of a low threshold for activation of the T cell clone , in which peptide- MHC avidity is the over-riding determinant of the strength of ligand signal .
 ( cell line: T cell clone, None) , ( cell type: T cell, None) , ( protein: MHC, 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 line: T cell clone, None) , ( cell type: T cell, None) , ( protein: MHC, None) 