The association between immune infiltrate including CD8 + T-cells with prognosis has been shown for both primary and metastatic colorectal cancer [32–36] and suggests more anti-tumour immune activity in dHGP, which may contribute to the favourable OS and DFS for dHGP compared to non-dHGP [2, 3, 31]. This evidence concerns the gene CD8A and metastatic colorectal cancer.