Targeting PIM kinases in combination with immune checkpoint therapy. (A) The tumor microenvironment contains immunosuppressive immune cells, including myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs), that prevent anti-tumor responses. Tumor cells, MDSCs, and TAMs express programmed death ligand 1 (PD-L1), an immune checkpoint molecule that dampens cytotoxic CD8+ T-cell immune responses. (B) PIM inhibitors used in combination with immune checkpoint inhibitors decrease MDSCs and TAMs, increase CD4+ T cell proliferation, and increase CD8+ T cell activation, thereby promoting decreased tumor growth. Adapted from “Immune Checkpoint Inhibitor Against Tumor Cell”, by BioRender.com (2022). Retrieved from https://app.biorender.com/biorender-templates (accessed on 29 August 2022).