CD8A and neoplasm: PGE2 accumulates in the tumor microenvironment (TME), binds EP2/EP4 receptors and triggers downstream signaling (PKA, β-catenin, NF-κB, PI3K/AKT) that restrains conventional dendritic cell type 1 (cDC1) lineage function, enhances MDSC stability, suppresses CD8+ T-cell cytotoxicity and supports regulatory T-cell (Treg) activation (45).