FASLG and neoplasm: Additionally, they secrete cytokines such as interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α), which can directly affect tumor cells or activate other immune cells by engaging death receptors on target cells via Fas ligand (FasL) or TNF-related apoptosis-inducing ligand (TRAIL).In the presence of antibodies, NK cells recognize the Fc region of the antibody via the Fcγ receptor, leading to antibody-dependent cellular cytotoxicity (ADCC) (4).