CD8A and neoplasm: The changes in the infiltration levels of CD8+ T cells, CD4+ T cells and tumor-associated macrophages in the TME are related to the prognosis of a variety of malignant tumors, including urothelial carcinoma, melanoma, lung cancer, breast cancer and gastric cancer (Turley et al., 2015; Nishino et al., 2017; Mariathasan et al., 2018; Zeng et al., 2019).