To understand the composition of immune cells in primary and metastatic tumors, we identified the populations of innate immune cells, including CD11b+F4/80+ macrophages, CD11b+Gr1+ myeloid-derived suppressor cells (MDSC), and CD11c+ MHCII+ dendritic cells (DC); and adaptive immune cells including CD4+ T cells, CD8+ T cells, and CD4+Foxp3+ regulatory T cells (Treg), in primary and metastatic tumors. The gene discussed is CD8A; the disease is metastatic neoplasm.