The overall frequency of CD45RA+ influenza-specific CD8 T cells out of total CD8 T cells was similar in the old and the young; rather it was the proportion of CD45RA+ influenza-specific T cells out of the influenza-specific CD8 T cells that was higher, arguing that it was a loss of the less differentiated CD45RO cells that led to the higher proportion of CD45RA+ influenza-specific T cells in the older group. The gene discussed is CD8A; the disease is influenza.