CD8A and gastric cancer: The context of TMB identified at diagnosis represents the immune response and chemotherapy benefit, and variations in the numbers of CD8+ T cells, CD4+ T cells, macrophages, and cancer-associated fibroblasts infiltrating in the TME correlate with clinical outcomes in a variety of malignancies, including GC, melanoma, urothelial cancer, lung cancer, and breast cancer (Zeng et al., 2019; DeBerardinis, 2020).