further demonstrated that the TLR9 agonist ODN1585 enhances CD8+ T cell-mediated antitumor immunity in colorectal cancer peritoneal metastasis by suppressing retinol metabolism in fibroblastic reticular cells (FRCs) and reducing Tim4+ peritoneal resident macrophage (PRM) populations, thereby potentiating anti-PD-1 therapy (27). This evidence concerns the gene PDCD1 and colorectal cancer.