Prostaglandin E2 (PGE2) impedes CD8+ T cell-mediated immune responses reliant on conventional type 1 dendritic cells (cDC1) and curtails cDC1 infiltration into tumor sites by inhibiting natural killer (NK) cell production of chemokine (C-C motif) ligand 5 (CCL5) and chemokine (C motif) ligand 1 (XCL1) (Zelenay et al., 2015; Böttcher et al., 2018). Here, CCL5 is linked to neoplasm.