PDCD1LG2 and prostate cancer: In cancer promotion, prostate cancer-infiltrating MSCs are reported to mediate their immunosuppressive effects by suppressing the proliferation of T cells in a dose-dependent manner, and to upregulate the cell surface levels of programmed death ligand-1 (PD-L1)/programmed death ligand-2 (PD-L2) via IFN-γ/TNF-α signaling (19).