Within CRC microenvironment, there are multiple antitumor immune cells, including multiple kinds of immune cells such as effective CD8 cells, CD4 Th1 cells, Th17 cells, natural killer (NK) cells, dendritic cells (DCs) and inflammatory Macs; whereas other immune cells such as MDSCs, immunosuppressive Macs (M2-like Macs) and N2 neutrophils, Tregs and Bregs can contribute to tumor growth. This evidence concerns the gene CD8A and neoplasm.