CD274 and neoplasm: One of the factors likely contributing to the poor prognosis of diffuse gliomas is their immunosuppressive microenvironment.6,7 Adult-type diffuse gliomas show a “non-inflamed” tumor niche, with abundant CD163+ (M2-like) anti-inflammatory microglia8 and low-to-moderate number of CD3+ tumor-infiltrating lymphocytes (TILs).9 These tumors express suppressive immune checkpoint molecules such as programmed death ligand 1 (PD-L1).