In more details, looking at the cytotoxic drugs commonly used in the treatment of mCRC, 5-fluoruracil (5FU) has a strong ability in selectively depleting tumour-associated myeloid-derived suppressor cells (MDSCs) and in increasing CD8+ tumour-infiltrating lymphocytes [21], while oxaliplatin potentiates dendritic cell (DC) functions and induces immunogenic cell death (ICD) and irinotecan inhibits the immunosuppressive environment [22, 23]. The gene discussed is CD8A; the disease is neoplasm.