As shown in Figure 8F, the expression of most immune checkpoint genes, including PD-1, PD-L1, PDCD1LG2, CTLA4, HAVCR2, LAG3, TIGHT and SIGLEC15, was obviously higher in the hepcidin high-expression group than in the hepcidin low-expression group of patients with LGG and GBM. Here, SIGLEC15 is linked to glioblastoma.