CD8A and neoplasm: Although it has been reported that CD8 + T cells, M1 and M2 TAMs are identified to play an important role in the development and progression of CRC, however, regarding the high density infiltration of NK cells in the tumor microenvironment is also important to inhibit tumor growth and metastasis in solid tumors such as colorectal cancer, lung cancer, etc. Its role in immunotherapy is also gradually recognized.