Fig. 2: Unique gene expression signature of PTGER4^hi CD8⁺ T cells in human cancer.

a UMAP projection displaying CD8⁺ T cell subsets (n = 26,709 cells). b Schematic of the PTGER4 group classification algorithm (top) and a violin plot illustrating PTGER4 expression in each PTGER4-expressing group of total CD8⁺ T cells population (bottom). c The percentage of each CD8⁺ T cell subset in different PTGER4-expressing groups (left) and the percentage of each PTGER4-expressing group in each CD8⁺ T cell subset (right). d Distribution of upregulated and downregulated genes in PTGER4^hi compared to PTGER4^lo CD8⁺ T cells in a total of 15 patient samples. e Gene set enrichment analysis (GSEA) of differentially expressed genes (DEGs) between the PTGER4^hi and PTGER4^lo groups in total CD8⁺ T cells for the pathways of interest: HALLMARK_IL2_STAT5_SIGNALING, HALLMARK_OXIDATIVE_PHOSPHORYLATION, and HALLMARK_MYC_TARGETS_V1. P-values were calculated using the adaptive multilevel splitting Monte Carlo approach and adjusted using the Benjamini–Hochberg procedure. NES normalized enrichment score. f Heatmap displaying log₂ fold change in expression levels of DEGs between the PTGER4^hi and PTGER4^lo total CD8⁺ T cells. The canonical genes in T cell activation, NFκB components, TCR and IL-2 signaling, mitochondrial oxidative phosphorylation (OXPHOS) and ribosomal proteins (RP) are shown. Source data are provided as a Source Data file.