While tumor-bearing WT mice exhibited Ag-specific division of OT-I CD8+ T cells in tumor tissues and TdLNs as well as OT-II CD4+ T cells in TdLNs, they did not show the apparent responses of OT-II CD4+ T cells in tumor tissues and Spl as well as OT-I CD8+ T cells in Spl (Figures 3A–L). This evidence concerns the gene CD4 and neoplasm.