In mouse models of breast and colon cancers, various methods of TGFβ inhibition increased the efficacy of PD-1/PD-L1 immunotherapies by reducing TGFβ signaling in stromal cells thereby facilitating CD8(+) T-cell penetration into the tumor and provoking robust anti-tumor immunity, ultimately leading to tumor regression4–6. Here, TGFB1 is linked to malignant colon neoplasm.