The NK profile in BC urine better resembles that of the tumor than the blood. (A) UMAP of 4,130 NK cells across BC blood, tumor, and urine. Cells are colored according to cluster. With a resolution of 0.5, there were 10 clusters. (B) Heatmap of top 10 genes for each NK cluster, displayed as averaged per cluster. (C) UMAP of NK cells split by tissue. (D) Bar-plot comparison of NK cluster frequency across tissue. (E and F) (E) Expression level of RGS1 and (F) an adaptive NK score across the clusters. (G) Average expression of NK markers associated with tissue residency and function across tissue. (H) Average expression of NK activating and inhibitory receptors and cytotoxic granules. (I and J) Volcano plot showing DEGs between NK cells in (I) urine versus tumor and in (J) blood versus tumor. (K) Pathways upregulated in NK cells in tumor versus blood. ESR, estrogen signaling receptor. (L) Volcano plot depicting DEGs between NK cells in urine versus blood. (M) Pathways enriched in urine versus blood NK cells. Cutoffs of log₂FC > |1| and P value <0.05 were used for volcano plots and pathway analysis.