a, b, Orthotopic PDAC mice (C57BL/6 WT, Pdcd1−/−, CD45.1) were treated with 500 ng of carrier-free rIL33 daily for 10 days (experimental designs shown in Fig. 4e, f). Live, CD45+, lineage−, CD90+, CD25+, ST2+ TILC2s were sort-purified to 98% purity at day 10 post-implantation. TILC2s (5 × 105 cells) were immediately transferred to orthotopic PDAC tumour-bearing ILC2-deficient (Rorafl/flIl7rCre/+) CD45.2 mice on days 7 and 14 post-tumour implantation via i.p. injection. Control mice received equivalent volumes of PBS via i.p. injection. a, Representative plots for TILC2 sort-purification (top) and post-sort purity (bottom). b, Representative plots showing PD-1 expression on sort-purified TILC2s from wild-type and CD45.1 mice in the experimental designs outlined in Fig. 4e, f. c, Survival and intratumoral CD8+ T cell frequency of orthotopic KPC 4662 and KPC 52 PDAC tumours; horizontal bars in c show median. d, Frequency of PD-1+ ILC2s (left) and correlation with PD-1+ T cells (right) in human PDACs. e, Linear regression analysis of IL33 and PDCD1 mRNA in bulk tumour transcriptomes from short- and long-term human PDAC survivors (left) and survival association of PD-1+ cells in tumour tissue microarrays of short- and long-term PDAC survivors (right); high and low defined as higher or lower than the median for the cohort. f, Model linking the IL33–TILC2 axis to T cell immunity in PDAC. ©2019, Memorial Sloan Kettering Cancer Center. g, Distribution of expression of costimulatory molecules in untreated TILC2s by scRNA-seq. Experimental design as shown in Extended Data Fig. 7a; data represent pooled purified single cells from biological replicates of n = 10 (vehicle). Data are representative of purity and PD-1 expression on sorted TILC2s in two independent experiments with n ≥ 4 per group (a, b). n and data points denote individual mice and patients analysed separately. P values determined by two-tailed Mann–Whitney test (c), two-sided log rank test (c, e, survival curves) and linear regression (d, e). Source data