CD4 and neoplasm: T cell frequency remained unchanged, but two-way ANOVA revealed that tumor growth significantly decreased the frequency of the subpopulation of T helper cells (CD4+/CD8−; p ≤ 0.05) and increased the frequency of cytotoxic T cells (CD4−/CD8+; p ≤ 0.05) most pronounced in the DIO/Tumor group (Fig. 5j–l).