A phase I study reports that adoptive infusion of natural killer (NK) cells is feasible and shows preliminary signals in patients with recurrent hepatocellular carcinoma after liver transplantation. Investigators focused on safety, tolerability and early antitumor activity in a heavily pretreated cohort. The report highlights manageable adverse events and instances of disease control, supporting follow-up dose-expansion trials and combination strategies. Authors emphasize the need to optimize cell source, conditioning regimens and immunosuppression management in transplant recipients.