In four independent GBM cohorts (TCGA (HG-UG133A), Rembrandt, GSE59612, and GSE16011), the upregulation of S100A9 mRNA was also verified, including 528, 219, 75, and 159 cases of human GBM tissues and 10, 28, 17, and 8 cases of NBTs, respectively (Figure 1C). Here, S100A9 is linked to glioblastoma.