Although the anti-Gr-1 Ab had no antitumour therapeutic effect in vivo (Figure 3(a)), the total number of P18-I10+ CD8+ T cells and the frequency of P18-I10+ cells among CD8+ T cells in the spleen were significantly increased in Gr-1-treated mice post-vSC25 infection (Figures 3(b) and 3(c)). This evidence concerns the gene CD8A and infection.