CD274 and central nervous system cancer: The initial use of checkpoint inhibitors, specifically pembrolizumab and nivolumab, in individuals with high-grade glioma has demonstrated limited efficacy [52-54], and the use of checkpoint inhibitors in a non-targeted population of individuals experiencing recurring high-grade glioma is not advised outside clinical trial settings. The assessment of programmed death ligand 1 (PD-L1) expression does not provide discriminatory value in predicting treatment response among patients [53,54].