A recent meta-analysis using 9 total studies, representing 806 GBM patients, showed that half of GBM patients have PD-L1 overexpression, and this expression in tumor tissues is significantly related to a poor OS (HR = 1.63, P = 0.003) with heterogeneity (I2 = 51%) [20]. The gene discussed is CD274; the disease is glioblastoma.