CD274 and central nervous system cancer: Zhu and coworkers [17] analyzed gene expression data and clinical information of about 1000 glioma patients from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) databases, finding a positive correlation of tumor PD-L1 expression with M2 polarization of infiltrating macrophages (M2-TAMs) along with an unfavorable prognostic significance of PD-L1 expression on GBM.