RUNX1 and glioblastoma: To validate the functional role of RUNX1 in GBM cells, we performed loss-of-function and gain-of-function experiment by either silencing RUNX1 (si-RUNX1) or overexpressing RUNX1 (pcDNA-RUNX1 expression plasmid) in both U87 and A172 cell lines (Figure 3a,b).