Conversely, tumor-activated γδ T cells could lyse tumor cells (Figure 4; n = 3, P < 0.01), and cytotoxicity for the tumor cells was increased in the presence of CD8+ T cells (P < 0.05), suggesting that tumor-activated γδ T cells not only directly kill tumor cells but also activate the cytotoxicity of CD8+ T cells. This evidence concerns the gene CD8A and neoplasm.