Macrophages showed the second-largest CCR4-associated decline (CCR4−/−: 5180 ± 1524 F4/80+ cells per 1 × 105 tumor cells vs. WT: 7563 ± 1524 F4/80+ cells per 1 × 105 tumor cells; n = 9, p = 0.0127), with a mean absolute reduction of 2383 ± 2155 (35%). The gene discussed is CCR4; the disease is neoplasm.