Fig 1: 4-NQO-induced lesions are not significantly impacted by the endogenous T cell response or treatment with checkpoint blockade monotherapies(A and B) 6- to 8-week-old littermates of indicated genotype were exposed to 4-NQO drinking water for 20 weeks, tongues were subsequently excised, and histopathology was quantified as in Figure 2A. n = 20 mice (Tcrb+/-Tcrd+/-), n = 11 mice (Tcrb+/-Tcrd-/-), n = 18 mice (Tcrb-/-Tcrd+/-), and n = 7 mice (Tcrb-/-Tcrd-/-).(A) Tumor incidence, where each mouse was scored once based on most severe histology grade observed. Summary plot of pooled data shows the percentage of mice scored as indicated histology grade. Each bar represents the cumulative data for mice of the indicated genotype.(B) Tumor burden. Summary plots of pooled data show the percentage of tongue perimeter defined as hyperkeratosis (left plot), dysplasia (middle plot), or SCC (right plot). Each symbol represents an individual tongue from a single mouse of the indicated genotype. Median is indicated.(C–E) 6- to 8-week-old female C57BL/6 mice were exposed to 4-NQO drinking water for 20 weeks. During the last 4 weeks of 4-NQO exposure, mice were treated intraperitoneally twice weekly with 100 µg anti-PD-L1 or isotype control monoclonal antibody. Tongues were excised at endpoint, and histopathology and IHC staining was performed and quantified as in Figures 2A and 2D. n = 10 mice per group.(C) Tumor incidence, where each mouse was scored once based on most severe histology grade observed. Summary plot of pooled data shows the percentage of mice scored as indicated histology grade. Each bar represents the cumulative data for mice that received indicated antibody treatment.(D) Tumor burden. Summary plot of pooled data shows the percentage of tongue perimeter defined as the indicated histology grade. Each symbol represents an individual tongue from a single mouse that received the indicated antibody treatment. Median is indicated.(E) Summary plot of pooled data from CD3 IHC density analysis, showing the number of CD3+ cells per mm2 for each lesion. Each symbol represents an individual lesion. Median is indicated. n = 6–52 lesions from 10 mice per group.Data are pooled from multiple independent experiments. Fisher’s test (A and C); one-way ANOVA, comparing all pairs in column (B); two-tailed nonparametric Mann Whitney test (D and E). NS, not significant. See also Figure S2.