CD56^bright NK cells respond most potently to IL-2 stimulation. (A) Dot plot (left) of selected markers of interest within unstimulated cells only (columns) across the different clusters (rows). The size of the dot represents the percentage of cells expressing the markers, and the color encodes the average scaled expression values. Heat map (right) of the same markers of interest within unstimulated cells only. Clusters are plotted in columns, and genes are shown in rows. Gene expression is color coded using average scaled expression values per cluster, based on a z-score distribution, ranging from low expression (purple) to high expression (yellow). (B) Comparison of average gene expression values for cluster 4 between unstimulated and IL-2–stimulated cells. Genes with a fold change >0.5 and Bonferroni-corrected P < .05 are highlighted. (C) Selected GO terms using all conserved markers upregulated or downregulated within this cluster with an adjusted P < .05. (D) Module scores for each NK cell cluster at the single-cell level, defined using the top 100 markers from bulk expression profiles of sorted CD56^dimCD16⁺ and CD56^brightCD16⁻ NK cells.⁴⁷  Module scores were calculated for unstimulated cells only. CD56^dim module score (left), CD56^bright module score (middle), and custom CD56^bright module score, excluding CTSW, DUSP1, JUN, FOS and CD69 (right). Violin plots represent the distribution of the module scores for each cluster, and the error bars represent the median and interquartile range. One-way analysis of variance with Bonferroni’s multiple comparison. Nonsignificant (n.s) P > .05; *P < .03; **P < .02; ***P < .0002; ****P < .0001.