PRF1 and neoplasm: Upon activation, they can exert powerful cytotoxicity against tumor- transformed cells by the release of molecules such as perforin and granzymes, of several chemokines such as MIP-1α/β, Chemokine (C-C motif) Ligand 5 (CCL5), Chemokine (C-X-C motif) Ligand 1 (CXCL1), and cytokines, such as Interferon (IFN)-γ, Tumor Necrosis Factor (TNF)-α, Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF), or Interleukin (IL)-10, which can differently modulate inflammatory responses [15,17,18].