White blood cells that ingest (phagocyte) substances and cells external or harmful to the organism, including microbes and cancer cells. M1 macrophages also enhances CD8+ cytotoxic T cells anti-tumor activity (Vlahopoulos, 2017) and promotes CD4+ helper 1 T cell differentiation (Lin and Karin, 2007). The gene discussed is CD8A; the disease is neoplasm.