Fig. 1

Domatinostat decreases tumor volume and induces strong CTL infiltration in the CTL-low CT26 tumor model. CT26 cells (1 × 10⁶) were inoculated s.c. into immunocompetent (a, c-e; n = 10 per group) and immunocompromised (b; n = 8 per group) BALB/c mice; when tumor volumes reached 150 mm³, animals were treated with domatinostat (20 mg/kg twice daily) or vehicle; after the end of treatment, tumors were harvested for flow cytometry and IHC. a, b, Tumor volumes in immunocompetent (a) and immunocompromised animals (b). c, CD3-AP (red) and CD8-DAB (brown) double IHC staining of the tumor core. d, Proportion of CD8⁺ and CD4⁺ T cells in tumors (upper panel) and blood (lower panel). e, Proportion of Tregs and CTL/Treg ratio in tumors. a, b, d, e, Mean ± SD showing all data points; P-values: Mann-Whitney test, two-tailed, **, P < 0.01; ***, P < 0.001; ****, P < 0.0001; ns, not significant