The Ectonucleotidase CD39 Identifies Tumor-Reactive CD8+ T Cells Predictive of Immune Checkpoint Blockade Efficacy in Human Lung Cancer

CD39 expression enriched for CD8+ T cells with features of exhaustion, tumor reactivity, and clonal expansion. Flow cytometry of 440 lung cancer biospecimens revealed weak association between CD39+ CD8+ T cells and tumoral features,