In Bcl9-depleted CT26 tumors, the ratio of tumor-infiltrated Treg was significantly decreased (Supplementary Fig. 1e, while the proportions of cytotoxic granzyme B (GZMB)+CD8+ T cells, IFN-γ+ CD8+ T cells, and effector CD8+ T cells were increased (Fig. 1f, g, Supplementary Fig. 1f), implying that Bcl9 depletion inhibits immunosuppressive immune cells. Here, BCL9 is linked to neoplasm.