In the tumor context, the production of prostaglandin E2 (PGE2) by tumor cells leads to cDC1 dysfunctionality marked by the downregulation of IRF8, and key effector cytokines such as CXCL9 and IL-12, resulting in poor CD8+ T cell tumor infiltration and ultimately in tumor immune evasion (82, 83). This evidence concerns the gene CXCL9 and neoplasm.