PDCD1 and central nervous system cancer: In the GL261 glioma model, the IIS risk score was significantly decreased after anti-PD1 immunotherapy (the expression levels of Emp3, Iqgap2, Mettl7b, Tnfrsf11b significantly decreased, and expression of Slc1a6 significantly increased) (Fig. 6H-L), while in the DSB glioma model, there was no significant change in the IIS risk score before and after anti-PD1 immunotherapy (Fig. S11A-E).