On the other hand, the cellular components are broadly consisting of non-immune (cancer-associated fibroblasts, cancer-associated adipocytes, tumor-associated pericytes, tumor endothelial cells, exosomes) and immune cells (natural killer T, tumor-infiltrating NK, invariant NKT, neutrophils, tumor-associated neutrophils, macrophages, myeloid-derived suppressor, dendritic cells, cytotoxic T lymphocytes, regulatory T cells, helper CD4+ T, cytotoxic CD8+ T and tissue-resident memory T cells) (Figure 2) [18]. The gene discussed is CD8A; the disease is neoplasm.