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 .
 T cell clone, T cell, MHC
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 T cell clone, T cell, MHC