Fig. 2
From: Roles of tumor-associated macrophages in anti-PD-1/PD-L1 immunotherapy for solid cancers
The release of multiple cytokines through TAMs affects PD-L1 expression. TGF-β upregulates tumor cell and PD-L1 expression of TAMs through the AKT/NF-kB or AKT/β-catenin pathway. IFN-γ upregulates PD-L1 expression by activating the transcription factor STAT1. PGE2 upregulates tumor cell PD-L1 expression by activating the PI3K/Akt/mTOR pathway. ILs upregulate PD-L1 expression in tumor cells through different pathways