(A) Heatmap showing the transformed ratio by column’s minimum MMI of selected markers for 7 populations (FlowSOM clustering using equal sampling and hierarchical consensus clustering) (left) and overlaid uniform manifold approximation and projection (UMAP) of the clusters found by FlowSOM analysis (right). TOX, thymocyte selection-associated high mobility group box protein; TIGIT, T cell immunoreceptor with immunoglobulin and ITIM domains. (B) Percentage of exhausted CD8⁺ T_EM cells, as found by FlowSOM clustering, within the CD8⁺ T cell population. (C) Percentage of TOX⁺CD8⁺ T cells within the CD8⁺ T cell population, including age-matched HCs (n = 6), and (D) percentage of PD-1^–TIGIT^–TOX⁺CD8⁺ T cells (left) and PD-1⁺TIGIT⁺TOX⁺CD8⁺ T cells (right) within the TOX⁺CD8⁺ T cell population, as found by manual gating. Diagnosis and all available relapse samples were used for FlowSOM clustering. Heatmap and UMAP shown for a representative experiment. Paired diagnosis and last relapse samples from n = 11 long-OS patients and n = 10 short-OS patients are included in the bar graph. Mean ± SEM shown. Statistical significance was determined by repeated measures 2-way ANOVA and Šidák’s multiple comparisons test on long-OS and short-OS patient samples. Data from HCs are also shown. P values are indicated where P < 0.05.