Tumor-infiltrated immune cells are dual, some of which has the effect of inhibiting tumor proliferation and metastasis, such as effector CD8+T (Teff) cells, memory CD8+T (Tmem) cells, natural killer cells (NK cells), B cells, M1 macrophages, dendritic cells (DCs), N1 neutrophils and so on, while others may be of benefit to the development of tumors, including Treg cells, M2 macrophages, myeloid-derived suppressor cells (MDSCs), and N2 neutrophils (62). Here, CD8A is linked to neoplasm.