a, Immunofluorescence images showing expression of IL-15 and CDH1 in tumor tissues from patients with colon carcinoma (left panel). Flow cytometric analysis of FCER1G and PD-1 expression in TCRβ+CD4− cells from the same tumor tissue (right panel). Data are representative of two independent experiments. b, Correlation between frequency of PD-1+ cells among CD45+TCRβ+CD4− cells and IL-15 expression level in tumor tissues from patients with colon carcinoma. Each dot denotes an independent patient sample. c, Statistical analysis showing relative mRNA expression of Il15 in sorted CD45−EpCAM+ cancer cells from S100a8-CreIl15fl/flPyMT (n = 3) and control PyMT mice (n = 3). d, Flow cytometric analysis of PD-1, NK1.1, and granzyme B expression in thymic αβILTCk progenitors (αβILTCkPs) one, three, or five days after culturing in the presence of 100 ng/ml IL-15/IL-15Ra complex. Data are representative of three independent experiments. e, A schematic diagram showing αβILTCk-based adoptive cellular transfer experiment. A constitutively active form of Stat5b (Stat5b-CA) was induced in thymic αβILTCkPs by tamoxifen administration one week after adoptive transfer into lymphocyte-deficient PyMT recipient mice with a total tumor burden of 300 – 400 mm3. f, Expression of Ly6G and TCRβ by tumor-infiltrating CD45+ cells. g, Statistical analysis of the frequency of donor-derived Ubc-CreERRosa26+/+ (n = 5) or Ubc-CerERRosa26LSL-Stat5b-CA/+ (n = 5) TCRβ+ cells among tumor-infiltrating CD45+ cells. h, Flow cytometric analysis of NK1.1 and granzyme B expression by donor-derived TCRβ+ cells in the tumor. i, Frequency of NK1.1+Granzyme B+ cells among transferred TCRβ+ cells. j, Total tumor burden in mice adoptively transferred with no cells or thymic αβILTCkPs of indicated genotypes. Data are pooled from three independent experiments. No transfer (n=4), Ubc-CreERRosa26+/+ (n=8), and Ubc-CreERRosa26Stat5b-CA/+ (n=7). k, A schematic diagram showing αβILTCk-based adoptive cellular transfer experiment. A constitutively active form of Stat5b (Stat5b-CA) was induced in thymic CD45.1+CD45.2+ αβILTCk progenitors or CD8 single positive T cells by tamoxifen administration one week after adoptive transfer into congenically distinct CD45.2+ PyMT recipient mice. All statistical data are shown as mean ± S.D (independent human samples in a-b, biologically independent mice in c,f-j and independent cell culture samples in d). Linear regression (b), two-tailed unpaired t-test (c,g,i) and two-way analysis of variance (ANOVA) (j) with post hoc Bonferroni t-test.. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001 and n.s.: not significant.