CD274 and central nervous system cancer: Zhu et al. [49], for instance, analyzing gene expression data from patients diagnosed with glioma from databases, like The Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA), found a positive correlation between tumor PD-L1 expression and the infiltration of alternatively activated (M2) macrophages, along with an unfavorable prognosis.