MMP9 and central nervous system cancer: A pairwise Pearson correlation analyses was used to compare the gene expression of P2X7R with each of the previously measured mediators/markers: tumour and glioma stemness markers – GFAP, IDH1/2, NANOG, SOX2, SOX2-OT and CD133; tumour-promoting mediators – IL-1β, IL-4, IL-6, IL-8, IL-10, IL-13, TGF-β, TNF, VEGFA/B, EGFR, MMP-9, HIF-1α, NF-κB and PCNA; tumour-suppressing mediators—IFN-α, IFN-β, IFN-γ, IL-2 and IL-12A/B; and immune cell markers—CD68, CD45, ARG1, CD14, S100A8/9, HLADR, FOXP3 and NLRP3 (Table 3).