CD274 and glioma: According to the WHO classification of Central Nervous System Tumors, 5th edition, WHO grade 4 gliomas (Figures 1, 2) exhibited a higher PD-L1 positivity rate of 27 cases (75%), whereas WHO grade 2 gliomas (Figures 3, 4) demonstrated a PD-L1 expression rate of six cases (66.7%) (Figure 5).