CD8A and colorectal carcinoma: Besides, the different CRC stages have distinct immune microenvironment, the CD4+, CD8+ T cells were significantly decreased and TAMs significantly increased in liver metastases, indicating T cell mediating immune responses was inhibited when TAM induced tumor cell metastasis by promoting angiogenesis [34], and promoted tumor cells disseminated to extravasation and survival by inhibiting immune-mediated elimination [35].