The beneficial effect of PD-1 blockade in DAC/IL-33 treated mice correlated with a significant increase in immune (CD45+) tumor-infiltrating cells, particularly CD4 and CD8 T cells and eosinophils (Fig. 3D) and with increased expression of IFN-γ, granzyme B (Gzmb), perforin (Prf1) and tumor necrosis factor-α (Tnf, Fig. 3E), indicating activation of effector anti-tumor immunity. Here, CD4 is linked to neoplasm.