In U87-MG GBM cells, however, wildtype POU5F1-Luc and POU5F1∆ets2-Luc reporters were upregulated to similar levels in Elk-1-VP16 overexpression (1.2 units in Figure 7Di and 1.5 units in Figure 7Diii), while POU5F1∆ets1-Luc was upregulated more (2.4 units, Figure 7Dii), and upregulation was significantly less in POU5F1∆ets3-Luc reporter (Figure 7Div). Here, ELK1 is linked to glioblastoma.