They themselves often express ICs, especially PD-L1.51 Although immunohistochemistry (IHC)-based research has found comparatively low PD-L1 positivity on tumor-infiltrating leukocytes outside of the trial context,52 a recent flow cytometric study revealed that approximately 95% of TAMs (defined as CD14+/HLA-DRhigh) were PD-L1+, and that positivity was more common in TAMs (and other myeloid-lineage cells) than in non-immune (CD45−) cells.20 Expression of other ICs on TAMs is still poorly understood in MPM. The gene discussed is CD274; the disease is neoplasm.