We further analyzed the D b NPN3A + Vb9 + CD8 + set that was prominent in 2 of the HK-NPN3A secondarily challenged mice. An average of 1.561 TCRb clonotypes was found within this population (Table S2) . Again, the D b NPN3A + Vb9 + CD8 + TCRb repertoire emerged as essentially restricted and private. However, TCRb analysis within other Vbs for NPN3A + CD8 + T cells would need to be performed to compare the whole TCR repertoires.