A significant enhancement of lymphocytoxicity of PBMCs and its secretion of cytokines (IL-6, IFN-γ, granzyme B, and TNF-α) were observed in the presence of PD-1 inhibitor than the control in co-culture system of A20-knockdown CRC cells and PBMCs (Fig. 2f–i and Supplementary Fig. 1l–o). Here, TNF is linked to colorectal carcinoma.