PRF1 and neoplasm: Once recruited into the TME, tumor-infiltrating Vδ1+ and Vδ2+ γδ T cells can eliminate tumor cells via TNF-related apoptosis-inducing ligand (TRAIL) (143), Fas/Fas ligand pathway (144), induction of antibody-dependent cellular cytotoxicity (ADCC) on antibody-opsonized tumor cells through CD16 (FcγRIII) (60, 145, 146), perforin/granzymes, IFN-γ/TNF-α secretion, and NKG2D-mediated cytotoxicity (13, 147).