CD274 and neoplasm: Meanwhile, due to the existence of negative feedback mechanism, when dMMR activates the anti-tumor immunity of the body, it will increase the expression of immunosuppressive factors at the same time, which will activate the PD-1/PD-L1 immune pathway of T cells and inhibit the activity of T cells, these immunosuppressive factors, especially γ-IFN, will produce a strong stimulation effect on the expression of PD-L1 of the TCs when the content of γ-IFN increases.