A phase I clinical trial reported that infusions of natural killer (NK) cells produced promising safety and feasibility signals in patients with recurrent hepatocellular carcinoma after liver transplantation. The trial, led by Yang, Gong and colleagues, tested adoptive NK-cell therapy in a high-risk population and documented tolerability alongside preliminary anti-tumor activity. Investigators emphasized the unmet need for effective, transplant-compatible immunotherapies in recurrent HCC. Sponsors and transplant centers will be watching for dose-expansion cohorts and biomarker correlations that could support later-stage trials.