Mechanisms of tumor cell evasion from NK cell-mediated killing and advances in NK cell-based cancer immunotherapy

Natural killer (NK) cells represent a critical component of the innate immune system, capable of exerting potent cytotoxic activity against infected and transformed cells. However, tumor cells evolve diverse strategies to evade NK cell-mediated surveillance, including modulation of receptor-ligand interactions, secretion of immunosuppressive cytokines, metabolic disruption, and induction of NK cell exhaustion. In this review, we summarise the mechanisms by which tumors escape NK cell control and highlight recent advances in NK cell-based immunotherapies, including adoptive NK transfer, immune checkpoint blockade, and CAR-engineered NK cells. Ongoing efforts to improve NK cell persistence, infiltration, and functional resilience hold promise for optimising clinical efficacy.