CD8A and neoplasm: We determined the ratio of effector to regulatory T cells since this may be decisive in determining whether an anti-tumor immune response is effective.[28] The mean ratio of IFN-γ+ CD8+ T cells to Treg in blood was 60.0, SD 66.6 and in tumors was 9.4, SD 8.8 (p = 0.02) (Figure 5A).