CD8A and malignant colon neoplasm: We investigated the percentage of 22 different subtypes of infiltrated immunocytes in each colon cancer patient and found that CD8+ T cells, activated CD4+ memory T cells, activated NK cells, and M1 macrophages were increased in the high-TMB group, indicating that the immunocyte-killing activity was increased in high-TMB colon cancer patients (Figures 4C,D), which is consistent with recent studies in gastrointestinal system malignancies (Zappasodi et al., 2018; Eso and Seno, 2020).