Group 1 ILC–derived TGF-β1 signals through autocrine mechanism. (A) Flow cytometric analysis of sorted splenic NK cells from indicated mice after in vitro culture for 48 h with minimal IL-15 (10 ng/ml) and TGF-β (5 ng/ml). (B) Analysis of donor-derived liver group 1 ILCs 6 wk after reconstitution with mixed BM from WT and Ncr1^CreTgfb1^fl mice, referring to Fig. 1, K–M. (C) Representative flow cytometry plots and quantification of SG CD8⁺ T_RM cells in WT, Ncr1^CreTgfb1^fl, and Ncr1^CreTgfbr2^fl mice. (D) Representative flow cytometry plots of blood NK cells 2 wk after birth. (E) Representative flow cytometry plots showing EYFP expression in SG group 1 ILCs of Id2^CreERT2R26R^EYFP mice at indicated age after tamoxifen treatment on P12. (F and G) Single-cell transcriptomes of group 1 ILCs from 3-wk-old SGs were analyzed for enrichment of TGF-β imprinting-associated genes (E) and expression of indicated genes (F), referring to Fig. 2, E–I. (A, C, and D) Data representative for one of two independent experiments. (B) Pooled from two to three independent experiments. Error bars display means ± SD. Statistical significance was calculated using one-way ANOVA or two-tailed t test; ns, not significant.