In addition, expression distribution and heatmap analysis indicated that 8 immune checkpoint related genes, including SIGLEC15, IDO1, CD274, HAVCR2, PDCD1, CTLA4, LAG3, and PDCD1LG2, were differentially expressed in LGG and GBM compared to normal tissues. This evidence concerns the gene PDCD1LG2 and glioblastoma.