In addition, we identified by single-cell RNA-seq analysis (Supplementary Figure 3E) that S100A9 is coexpressed in myeloid cells with genes that define an immune suppressive profile (a hallmark of GBM microenvironment) such as CLEC5A,29 MS4A4A30 and TREM1,31 one of them confirmed by IF on male GBM tissue (Figure 4I). Here, S100A9 is linked to glioblastoma.