The data (Fig. 2c) show that memory CD8 T cells made a minor contribution to de novo influenza infection in the bronchoalveolar lavage (BAL), lung tissue and spleen when the naïve and memory cells were transferred in a 1:1 ratio, and a greater contribution to the response when the cells were transferred in a 1:9 ratio, a ratio more reflective of their natural distribution in aged mice. The gene discussed is CD8A; the disease is influenza.