CD274 and diffuse large B-cell lymphoma: For example, Dong et al. discovered that total PD-L1 and membrane PD-L1 protein were overexpressed in some DLBCL cells, and the AKT/mTOR pathway was activated by PD-1/Fc stimulation, which indicated that PD-1/PD-L1 directly activated the intracellular oncogenic signaling pathway in tumor cells [21].