Increased IL-12–dependent NK cell recruitment. (A) Neutralizing IL-12p40 but not IL-23p19 rescued the antitumor effect of adoptively transferred IKKβ^DN BMDMs (P < 0.01; Mann-Whitney test). Data are represented as mean ± SEM of n = 6. Representative data are shown from two independent experiments. (B) Representative bioluminescence image of the IL-12p40–neutralizing experiment (n = 6). (C) Adoptive transfer of IKKβ^DN BMDMs increases NK cell recruitment in ID8 tumors (P < 0.01; Mann-Whitney test). Data are represented as mean ± SD of n = 6. Representative data are shown from two independent experiments. (D) Ex vivo NK cell cytotoxicity assay. Splenic DX5⁺-enriched NK cells were stimulated with ascites from tumor-bearing mice, which had either no treatment or were treated with adoptive transfer of mock or IKKβ^DN BMDMs. Ascites from mice treated by adoptive transfer of IKKβ^DN BMDMs led to a significant increase in NK cell–mediated tumor cell cytotoxicity (P < 0.01; t test with Welch's correction). The addition of a neutralizing antibody against IL-12p40 but not IL-23p19 or the respective control antibody rescued the increased tumoricidal effect. Data are represented as mean of n = 3. Representative data are shown from three independent experiments.