A multi-cohort genomic analysis reports that lung adenocarcinoma tumors show marked natural killer cell depletion and a redistribution of NK states away from cytotoxic competence. Investigators argue that the resulting “state balance” could become a biomarker for immunotherapy response, reflecting a shift from simply counting immune cells to assessing their functional state. For immuno-oncology, the work highlights an analytical framework that may better explain why patients with similar baseline immune infiltration can respond differently.