Extended Data Fig. 1: PGE₂-EP2/EP4 axis is associated with decreased IL-2 mediated TIL expansion.

a, Violin plot of IL-2 signalling score in tumour reactive / non-tumour reactive CD8⁺ TILs clones that expanded or did not expand in the cell-therapy product. Number of clonotypes and cells are shown. b, Top 35 Reactome pathways negatively associated to IL-2 signalling in CD8⁺ TILs from melanoma patients enrolled in the TIL-ACT trial (n = 13). In red are the pathways associated with PGE₂ signalling. c, Correlation per patients between eicosanoid ligand binding receptors score in CD8⁺ TILs and total number of pre-REP TILs (n = 13). d, Violin plot of PGE₂ signature score in tumour reactive/non-tumour reactive CD8⁺ TILs clones that expanded or did not expand in the cell-therapy product. Number of clonotypes and cells are shown. (a,d):Boxplots display smallest and largest values in the dataset. Box hinges: first and third quartile with centre as median. Whiskers: 1.5x interquartile range (IQR) from the first and third quartiles. Statistical comparisons were performed with one-way ANOVA with Tukey’s multiple-comparisons test (a, d) and two-sided Spearman’s correlation (c) or Pearson’s correlation (b). Independent patients were used as biological replicates with exact numbers listed in each panel.